A day after the US Senate passed a spending bill to end the longest-ever government shutdown, the budget fight now moves to the House of Representatives.

The lower chamber of Congress is expected to vote this week on the funding measure.

Unlike in the Senate, if House Republicans stay united, they don’t need any Democrats to pass the budget. But the margin for error is razor thin.

Here are four potential hold-ups for the budget, before it can clear Congress and land on the president’s desk for signing into law.

Will House Republicans budge on healthcare?

A key sticking point throughout the shutdown has been a desire on the part of Democrats to attach to the spending bill a renewal of tax credits that make health insurance less expensive for 24 million Americans.

Senate Republicans instead only agreed to grant Democrats a vote in December on whether to extend the subsidies – something they had already offered weeks ago.

And House Speaker Mike Johnson would not commit on Monday to allowing a vote in his chamber on the tax credits.

This entails a fair degree of political risk for Republicans, however. If they torpedo the subsidies, health coverage premiums could rocket, handing Democrats a ready-made campaign issue for next year’s midterm elections.

Marjorie Taylor Greene, a conservative Republican congresswoman from Georgia, has broken ranks with President Donald Trump to warn that her party must ensure health insurance premiums do not spike.

As the clock ticks down to the subsidies expiring by the end of December, Republicans are working out their plan.

They want income caps on who can receive the tax credits, and are proposing the tax dollars bypass insurance companies and go straight to individuals – although the details are unclear.

How intense will House Democratic opposition be?

Out of power in Washington, where Trump’s Republicans control the House and Senate, Democrats appeared finally to have some political wind in their sails after a handful of election wins last week in Virginia, New Jersey and New York City.

But those victories, like the shutdown fight, have accentuated strategic tensions between the pragmatic and progressive, or left-wing, factions of the party.

The Democratic left is furious at defectors who voted with Senate Republicans to pass the budget on Monday, seeing this as a capitulation to Trump.

From that wing of the party, Senator Bernie Sanders of Vermont said giving up the fight was a “horrific mistake”. California Governor Gavin Newsom called it “surrender”.

Congressman Greg Casar of Texas, the chairman of the House Progressive Caucus, warned: “A deal that doesn’t reduce healthcare costs is a betrayal of millions of Americans counting on Democrats to fight for them.”

However, centrist lawmakers like Jared Golden of Maine, who represents one of the most conservative districts in the nation held by any Democrat, may cross the aisle.

Golden, who recently announced he won’t run for re-election, is likely to vote for the package, his office indicated to Axios, a political outlet, on Monday.

Another moderate Democrat, Henry Cuellar of Texas, could help get the Republicans’ spending plan over the line.

“It’s past time to put country over party and get our government working again for the American people,” he posted on social media on Sunday.

The world must “defeat” climate denialism and fight fake news, Brazil’s President Luiz Inácio Lula da Silva has told the opening meeting of the UN climate talks.

In a rallying cry to COP30, President Lula again made thinly-veiled references to President Donald Trump who branded climate change “a con job” in September.

The two weeks of talks kicked off on Monday in the lush Brazilian city of Belém on the edge of the Amazon rainforest.

They take place against a fraught political backdrop and the US has sent no senior officials.

On Monday thousands of delegates poured into the COP venue in a heavily air-conditioned former aerodrome, some coming from accommodation in shipping containers and cruise ships moored on the riverside.

Members of the Guajajara indigenous group, in traditional dress, performed a welcome song and dance for assembled diplomats.

Addressing the conference, President Lula said “COP30 will be the COP of truth” in an era of “fake news and misrepresentation” and “rejection of scientific evidence”.

Without naming President Trump, President Lula continued, “they control the algorithms, sew hatred and spread fear”.

“It’s time to inflict a new defeat on the deniers,” he said.

Since President Trump took office in January, he has promised to invest heavily in fossil fuels, saying that this will secure greater economic prosperity for the US.

His administration has cancelled more than $13bn of funding for renewable energy and is taking steps to open up more areas of the US to oil and gas exploration.

That puts the country at odds with the majority of nations still committed to reducing greenhouse gas emissions and investing in green energy.

This backdrop has put the COP talks in a difficult position as nations aim to make progress on tackling climate change without the participation of the world’s biggest economy.

Some delegates fear that the US could still decide to send officials to undermine the talks. Other environmental talks collapsed this year following US pressure, labelled “bully-boy tactics” by some participants.

Addressing officials in Belém, UN climate chief Simon Stiell initially struck an optimistic tone. He said significant progress had been made in the last decade to reduce emissions of planet-warming gases.

But then he took aim at “squabbling” between countries.

“Not one single nation among you can afford this, as climate disasters rip double-digits off GDP,” he said.

Brazil wants to use its presidency of the talks to secure progress on key promises made in previous years.

That includes moving away from the use of planet-warming fossil fuels, finance for developing countries on the frontline of climate change, and protecting nature.

President Lula’s centrepiece is a fund called the Tropical Forest Forever Facility (TFFF) that Brazil hopes will raise $125bn to protect tropical forests globally.

But fund-raising got off to a slow start, particularly after the UK decided at the last minute not to contribute public money.

Nations are yet to agree on the conference agenda.

Countries with competing interests are lobbying for new items to be added, including a plea from a coalition called Alliance of Small Island States (AOSIS) that includes Caribbean and Pacific countries at most risk from rising seas and rising global temperatures

The group called for the COP to discuss the long-held goal of keeping global temperature rise to 1.5C.

But in recent weeks even the UN has said it accepts that overshooting this temperature is “inevitable”.

Last week UN General Secretary General António Guterres told leaders in Belém that the failure to limit global temperature rise to 1.5C was a “moral failure and deadly negligence”.

Seven Senate Democrats plus one independent voted on Sunday to support a Republican deal to reopen the US government.

The defections broke a weeks-long deadlock during which the Democratic Party resisted pressure to end the longest ever US shutdown.

During that period, the main reason the Democratic senators gave for refusing to back a funding deal was the expiry of healthcare subsidies – which they said would hit millions of households.

So who are the group who sided with the Republicans – and what have they said to justify crossing the floor?

Tim Kaine

The first thing to say about them all is that none of them faces re-election in 2026, and Virginia Senator Kaine is no different.

Known to many as Hillary Clinton’s running mate in the 2016 presidential election, he said he backed the Republican deal because it would protect workers and set the US on a path towards “fixing Republicans’ healthcare mess”.

• US Senate advances deal aimed at ending shutdown

His state is home to about 300,000 federal employees, many of whom are off work without pay because of the shutdown.

He said: “This legislation will protect federal workers from baseless firings, reinstate those who have been wrongfully terminated during the shutdown, and ensure federal workers receive back pay, as required by a law I got passed in 2019.”

Jeanne Shaheen

The New Hampshire senator was one of the architects of the deal that advanced on Sunday. She praised it as one that restores a cross-party spending process, including funds for food assistance and healthcare for military veterans.

“Weeks of negotiations with Republicans have made clear that they will not address healthcare as part of shutdown talks – and that waiting longer will only prolong the pain Americans are feeling because of the shutdown,” she said.

Maggie Hassan

New Hampshire’s other senator, Hassan told reporters her constituents had been hit hard by the shutdown and were now bracing for an impending spike in healthcare costs.

“My vote today was to do two things: both equally morally important and imperative,” she said.

Hassan spoke of the importance of a functioning government, “so that our kids eat, so that our elderly citizens eat, so that our air traffic controllers can get some sleep and earn money, get paid while they are working, so that our veterans are protected”.