Greater Manchester leaders have been given a deadline of midday to reach a deal with the government over moving to tier three Covid restrictions.
If a deal is not reached, Communities Secretary Robert Jenrick said the PM would decide on the next steps.
In this situation, the BBC’s Laura Kuenssberg said the “implication” was the top tier of rules would be imposed.
Greater Manchester Mayor Andy Burnham said the region was seeking a “fair figure” of support from the government.
Mr Burnham told BBC Radio 4’s Today programme he would be meeting with local leaders this morning and would advise them to set out the request in a letter to the government.
The government and local leaders – including mayors and MPs – have been embroiled in 10 days of talks over moving Greater Manchester’s 2.8m population from tier two to the highest restrictions.
Greater Manchester has been under local restrictions since July.
The “very high” alert level – also known as tier three – would mean closing pubs and bars which do not serve meals, and additional restrictions on households mixing.
Mr Jenrick said local leaders had been “so far unwilling to take the action that is required to get this situation under control”.
Speaking to Today, Mr Burnham described the government’s “late-night ultimatum briefed to the media” as a “slightly provocative move”, but he said he was going to “try and find a way forward”.
He said local leaders had never been given a figure for additional financial support in return for further restrictions.
As well as setting out what a “fair figure” of support was, Mr Burnham said he wanted “full flexibility” to support people who will be affected by restrictions.
He said: “I think it is fair to recognise that if you put a place under restrictions for as long as we’ve been under restrictions it grinds people down. It pushes businesses closer to the brink.”
Mr Burnham said he would not “break the law” if no agreement was reached between both sides and the government imposed tier three measures on Greater Manchester.
“It’s their prerogative to do what they think is needed,” he told BBC Breakfast.
“But I would say to them that I don’t think it will help us bring people with what they want to do to control this virus. I think it would be better to come to an agreement.”
Mr Burnham also said he thought the shielding of elderly and vulnerable people in Greater Manchester needed to be “looked at seriously” and suggested it was “part of the solution”.
Sir Richard Leese, the Labour leader of Manchester City Council, told BBC Newsnight he hoped a deal could still be made, but added: “If government imposes tier three – and I hope that won’t happen – we will clearly need to comply with that.”
On Monday, Mr Burnham and Sir Richard accused the government of using “selective statistics” on hospital occupancy rates to bolster the case for tougher rules.
On Monday evening, the two sides couldn’t even agree on what they actually discussed earlier.
Believe the local leaders and on Monday morning there seemed to be hope in the air. Officials from central government had mooted the possibility of a hardship fund to help support low-paid workers who stand to lose out if businesses close their doors under tighter restrictions.
The message local leaders took from their meeting was that, while the Treasury is adamant they are not going to extend their national furlough scheme – nor increase the level of cash available from its replacement, the Job Support Scheme – Westminster might sign off extra money that could be spent that way, if local politicians saw fit.
There was no concrete agreement on the numbers, but sources in Greater Manchester suggest the cost of supporting those who need the extra help comes in at around £15m a month.
After that call, the consensus among North West leaders was moving in the direction of signing on the dotted line, with another call planned with Communities Secretary Robert Jenrick for the afternoon.
But rather than ushering in a new spirit of co-operation, that meeting went south.
Why does the government want tougher restrictions?
A three-tier system of alerts was announced a week ago in an attempt to control rising coronavirus cases without a UK-wide lockdown.
Mr Jenrick said Greater Manchester hospitals now had more Covid-19 patients than the whole of south-west England and south-east England combined.
Prime Minister Boris Johnson said on Friday that he might “need to intervene” if local leaders did not accept a move to tier three.
Why haven’t Greater Manchester leaders agreed a deal?
Local councillors, the mayor and MPs are concerned that tier three rules will devastate industries such as hospitality without more financial support for workers and businesses.
A key sticking point is that Mr Burnham wants the government to reintroduce the 80% furlough scheme used during the UK’s first lockdown, instead of the new Job Support Scheme which covers 67% of the wages (covered by employers and the government) of people affected by tier three closures.
Where else are tougher restrictions being introduced?
Health Secretary Matt Hancock told the House of Commons further discussions were planned about South Yorkshire, West Yorkshire, Nottinghamshire, north-east England and Teesside moving to tier three, or very high alert.
In Wales, people will be told from Friday to stay at home, while pubs, restaurants and non-essential shops will shut, as part of a “short, sharp” national lockdown until 9 November.
It comes as a two-week school closure begins in Northern Ireland as part of a tightening of restrictions.
In Scotland, the tightest restrictions are in place in the central belt, and there are plans for a three-tier framework of measures, similar to England’s.
How bad is the spread of the virus in the UK now?
Monday’s figures show the UK recorded a further 18,804 coronavirus cases and 80 deaths.
Mr Hancock said the virus was “on the offensive” as winter approached, adding that he was concerned about the level of infections among over-60s in some northern areas.
But as the government tries to tackle the virus region by region, its claims about the impact on each area have been disputed.
On Monday, the prime minister’s official spokesman said government projections suggested coronavirus patients would take up the entire current intensive care capacity in Greater Manchester by 8 November, not including capacity in Nightingale hospitals.
But Prof Jane Eddleston, the region’s medical lead for the coronavirus response, said the situation was “serious” but Greater Manchester’s intensive care capacity was not at risk of being overwhelmed.
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