The UK Chancellor Phillip Hammond is set to offer emergency funding to local councils to foot increasing costs in social care.

He is also expected to promise a "root-and-branch" review of the social care system later in the year, when he announces his Budget later this month, Sky News reports, quoting government sources.

"[Prime Minister Theresa May] is looking at this in the short, medium and long term," a government source said.

The cash injection is expected to run into hundreds of millions of pounds, the broadcaster said amid reports that May faces backbench rebellion if there is no relief in the Budget on 8 March.

"I was disappointed in the Autumn Statement that nothing came out of that," Tory MP Johnny Mercer said. "I think if nothing comes out of the March Budget, you are going to see a group of us exerting a significant amount of pressure in social care," he said.

The broadcaster noted that Mercer was one of the rebels who had forced former chancellor George Osborne to make a U-turn over disability cuts.

Mercer added: "We do not raise enough money [in council tax] to make a difference on how we look after our old people. These are frontline seats.

"If modern compassionate conservatism is going to become a reality rather than something talked about in London, this is something that we have got to get right, so of course I am going to get together with others in a similar position if we don't get it right."

Under government plans unveiled in December 2016 by Communities Secretary Sajid Javid, local councils would be allowed to hike council tax bills by an extra 3% this year and another 3% in 2018 to plug the funding gap but only if they spend it on social care.

However, the Local Government Association (LGA) has highlighted the fact that these rate hikes are unlikely to even close the funding gap, with councils seeing an estimated £2.6bn deficit in their social care budgets by 2020.

May has asked Whitehall to look at various options such as revisiting the death tax and a 10% levy on all estates in addition to the inheritance tax, now at 40% on estates above £325,000.

This week, Plymouth voted for a 4.4% hike in council tax bills, with a 2.49% social care precept in addition to the annual 2% hike councils can impose.