Businesses across London urgently need extra financial support to deal with a "difficult winter" of heightened coronavirus restrictions, firms and politicians have demanded.

The calls were echoed in Essex, which will move with the capital into Tier 2, or "high", on the Covid alert levels on Saturday, meaning households will be banned from mixing indoors, including in pubs and restaurants.

There are concerns the move will have a significant impact on businesses that are already reeling from the faltering economy and the national lockdown earlier this year.

London Mayor Sadiq Khan, like many MPs, said the move was necessary to combat a resurgence of Covid-19 but said he would continue to call for additional financial support.

"I must warn Londoners that we've got a difficult winter ahead," he told the London Assembly.

"But - just as we've always done throughout our city's great history - I know we'll get through this dark time by pulling together."

Tory MP Nickie Aiken, who represents the Cities of London and Westminster, also added her voice to calls for financial help.

"Many of our businesses are already on their knees, and I urge the Government to consider further support before they disappear for good," she said.

Labour shadow minister and Ilford North MP Wes Streeting said the new restrictions in London would keep businesses open "in name only" as he called for more economic support.

He told the PA news agency: "There are lots of restaurants, pubs, bars and other venues whose doors will be open but customers will just not be walking through the door.

"That's why the Government's economic support for businesses needs to live up to the reality of the lockdown restrictions."

Mr Streeting, like the mayor, argued a better approach would be a short national lockdown known as a "circuit-breaker", which has been advocated by the Government's Scientific Advisory Group for Emergencies.

The decision has been made to move the entire capital into the middle tier of restrictions as one, despite rates varying across London.

Ealing is the worst-hit borough with 145 new cases per 100,000 in the week up to October 10, while Bexley is the lowest on 69.

Senior Conservative Sir Bob Neill, who is the MP for Bromley and Chislehurst, told Sky News: "I think it's a mistake. I think it's disproportionate for the whole of London."

He argued areas in the South East, like his own constituency, have "very much lower" rates than others in the capital.

"And although they are increasing, I think to move this way for the whole of London, this one size fits all approach, is a mistake because of the very real harm it will do to businesses," he added.

But Rupa Huq, the Labour MP for Ealing Central and Acton, said the move to Tier 2 was mere "tinkering" and said a circuit-breaker was needed to stop the virus "spreading like wildfire".

While workers in businesses forced to shut by Tier 3 restrictions will get two-thirds of their wages paid for by the Government, there is no extra funding for entering Tier 2.

London Chamber of Commerce chief executive Richard Burge said: "Hospitality businesses are between the rock and hard place. Their trade is impacted by the restrictions, yet there's not sufficient support available to help them to stay open.

"The Chancellor must realise his funding packages are focused on recovery, but for the next few weeks we will not be recovering, we will be surviving - and his financial support must reflect that reality or businesses will fail.

"He must urgently reassess what support is available, particularly to the hospitality sector, in a Tier 2 area."

In Essex, Harlow MP Robert Halfon said he would welcome Tier 2 measures for the county but would call on Chancellor Rishi Sunak to prevent businesses suffering financially from the move.

The senior Conservative MP told PA: "Sadly I support the Tier 2 measures... because otherwise if we don't act early we could face a situation, a real struggle, that sadly so many northern towns and cities are facing at this time.

"I will be writing to the Chancellor to ensure that, as far as possible, alongside the existing scheme, that businesses do not suffer financially because of the move to Tier 2."