TORY grandee Lord Patten has warned his colleagues that if Theresa May cuts a deal with the "toxic" Democratic Unionists, it could make the Conservatives look like the "Nasty Party" again.

The former Cabinet minister spoke out as Downing Street continued to try to reach an agreement with DUP leader Arlene Foster and her 10 MPs, whose number would give the Prime Minister a working majority in the Commons.

However, time is running out. The key Commons debate on the Queen’s Speech will take place on Thursday.

Sir Jeffrey Donaldson, the DUP’s chief whip, has said he believed the chances of reaching a deal were “very good”. It is believed the Northern Irish party’s price will be more money for public services and infrastructure although the mooted figure of £2 billion a year has been denied by the DUP.

Priti Patel, the international development secretary, told ITV’s Peston on Sunday she understood the inter-party talks were “progressing in the right way” and a deal would “come to the conclusion at the right time when when all parties have agreed”.

But Lord Patten told the same programme: "The DUP is a toxic brand and the Conservative Party has got itself back in to the situation where there's a danger of it looking like the 'Nasty Party', to borrow from Theresa May.

"What the DUP want to do is to sell their votes at every opportunity and this on the assumption that somehow Northern Ireland has been disadvantaged by public spending over the years. I mean, tell that to the Marines; Northern Ireland has got a lot of public spending over the years."

The former Tory chairman said the DUP would continually squeeze the Government for more concessions.

"Every vote will cost you," he declared. "Every vote, you will have to find some way of paying for it and then explain to the Scots and the Welsh and people in the North East why they can't have the same thing too."

Experts have pointed out that any extra money for Northern Ireland would not lead to financial consequentials for Scotland, England and Wales under the Barnett Formula.

However, the Conservative peer said there was little prospect of the DUP bringing down the Government.

"If there isn't an agreement with the DUP, are the DUP going to bring down a Conservative Government in order to bring in Mr Corbyn, who has a certain relationship with the IRA in the past? Of course, they're not," he added.

The expectation at Westminster is that Ms Foster will fly to London for Downing Street talks to seal the deal in the next 48 hours.