LONDON, July 10 (Xinhua) -- With the number of resignations sent to Theresa May reaching five since her landmark Chequers meeting, Britain's prime minister insisted Tuesday night she can deliver an orderly departure from the European Union (EU).

The latest blow came as media in London reported that one Conservative member of parliament (MP) has submitted a formal letter calling for a confidence vote in May as the leader of the party.

Andrew Bridgen became the first Conservative MP to publicly confirm he had sent a letter calling for a vote of confidence in the prime minister, it was reported.

If a further 47 Conservative MPs send in letters it will trigger a vote of confidence in the leader. Political experts said May would beat any contenders, but facing a confidence vote would dent her credibility, even if it fails to see her replaced.

The Daily Telegraph said Tuesday night that senior Brexiteers said that they have enough letters in hand to trigger a confidence vote and will submit them unless she hardens her Brexit plans.

"If the policy doesn't change the letters will go in," one Eurosceptic Conservative MP told the newspaper, adding that "her deal will be rejected by Brussels, Downing Street must know that. They are either being incompetent or disingenuous."

Both Rookie MP Ben Bradley, who only won a seat in the House of Commons last year, and Maria Caulfield, elected in 2015, resigned as vice chairs of May's governing Conservative Party, citing disagreement with the soft-Brexit announced at a meeting Friday of her full cabinet.

Their departure followed that of Foreign Secretary Boris Johnson, Brexit Secretary David Davis and Davis' number two, Brexit Minister Steve Baker.

Bradley said the Chequers proposals would leave Britain tied to EU trade regulations. He told May he believed the outcome would be the worst of all worlds for Britain.

Caulfield said in her resignation letter that "I cannot support the direction of travel in the Brexit negotiations, which in my view do not fully embrace the opportunities that Brexit can provide. The policy may assuage vested interests, but the voters will find out and their representatives will be found out. This policy will be bad for our country and bad for the party."

The direct consequences of that, she added would see main opposition leader Jeremy Corbyn moving into 10 Downing Street as a Labour prime minister.

On Monday night when addressing her backbenchers, May said without their support, Corbyn could run the country as prime minister.

Political commentators were predicting Tuesday that other Conservatives will quit their jobs in the coming days.

The Guardian newspaper reported Tuesday that hard Brexiteers in the Conservative party had threatened May with a "drip, drip" of resignations that would undermine her premiership.

Johnson has so far remained out of the spotlight since he resigned, and there has been little comment from potential leadership contender, leading pro-Brexit lawmaker, Jacob Rees-Mogg, who has been critical of May's proposals.

Tuesday started as a "business as usual" for May as she chaired the first meeting of her new look cabinet following her reshuffle prompted by the resignations.