The partial shutdown of the US government has entered its 22nd day – now becoming the longest closure in the country’s history.

Donald Trump is said to have privately considered declaring a national emergency to build a wall between the US and Mexico without a new stream of cash from Congress.

However, some of the Republicans have been fiercely debating that idea, and the president has urged Congress to come up with another solution.

“What we’re not looking to do right now is national emergency,” Trump said.

He insisted that he had the authority to do that, adding that he is “not going to do it so fast” because he would still prefer to work out a deal with Congress.

What is a government shutdown?

The closing of (some) government agencies and federally controlled buildings and sites.

Those deemed “essential” are spared but employees of the rest (around 40%) are placed on unpaid leave and told not to work.

A shutdown results from an impasse in the US government when Republicans and Democrats can’t agree on what should be included in the latest spending bill.

Why is this happening?

Trump and US congress have clashed over the American president’s call for five billion dollars (£3.9 billion) to build a border wall with Mexico and he has refused to approve a budget unless it includes funds for a wall on the Mexican border.

The Democrats have described the leader’s financial demands as “costly” and immoral.

The dispute has affected nine of 15 cabinet-level departments and dozens of agencies, including the departments of Homeland Security, transportation, the interior, agriculture, state and justice, as well as national parks and forests.

Who has been affected?

More than 800,000 federal employees have seen their jobs disrupted, many of whom have been forced to continue working without pay.

On Friday, some of these workers – including prison guards, airport staff and FBI agents – missed their first salaries of the year.

On Friday Senator Tim Kaine tweeted: “It should be payday for hundreds of thousands of federal workers. But thanks to Trump, many are actually getting pay stubs like this.

“He’s treating them like the countless contractors he stiffed throughout his business career.”

The financial stress is leading some workers to look for other jobs, ask relatives for money, apply for unemployment or even go without essentials like medication.

Meanwhile, other Americans are facing a host of inconveniences and hardships, from shuttered museums to delayed farm loans.

While they can be kept on the job, federal workers cannot be paid for days worked while there is a lapse in funding. In the past, however, they have been repaid retroactively even if they were ordered to stay at home.

The shutdown is a particularly raw deal for employees working under federal contracts, as they are not directly employed by the government and usually are not entitled to backpay. 

Rush hour in Washington DC, meanwhile, becomes easier to negotiate, as tens of thousands of federal workers are off the roads.

Has this happened before?

US government shutdowns happened every year when Jimmy Carter was president, averaging 11 days each. During Ronald Reagan’s two terms, there were six shutdowns, typically lasting just one or two days apiece. Deals were cut, and everyone moved on.

Until now, the longest one had been a 21-day shutdown starting in December 1995, amid a deadlock between then-President Bill Clinton and congressional Republicans.

Before a three-day lapse in January, caused by Democrats’ insistence that any budget measure come with protections for young immigrants known as “dreamers”, the most recent significant shutdown was a 16-day partial closure of the government in 2013.

That event came as Tea Party conservatives tried to block implementation of Mr Obama’s flagship healthcare law. The US government also shut for a few hours last February amid a partisan dispute over deficit spending.

What are the consequences?

Government shutdowns are expensive and can cause significant harm to the broader economy, as workers are forced to tighten their budgets due to missed pay checks and consumer confidence dampens.

The Bureau of Economic Analysis estimated that the 2013 shutdown of 16 days reduced GDP for the fourth quarter of that year by 0.3 percentage points.

The Internal Revenue Service is calling some employees back from furlough in order to process refunds after a change in policy from the White House.

And the Agriculture Department announced a complicated plan to continue food assistance for the poor into February, to keep people fed and avoid further economic damage.