Tory Lords are already in open revolt over his sacking of their leader Viscount Cranborne, with six of them resigning.

Chief Political Correspondent John Sergeant: "Worst crisis of William Hague's leadership"

Deputy leader Lord Fraser, who stepped down in protest, has been joined by five other Tory peers.

But Mr Hague insisted the problem was not serious as he had the backing of his MPs.

Now former minister David Curry has said there appeared to have been "a terrible failure of communication" between Lord Cranborne and Mr Hague.

And right-wing Tory MP Alan Clark said the row could damage the Conservative Party.

"Although it may look as though Mr Hague is asserting his authority, it seems to me that there is a very unwelcome separation now developing between the Lords and the Commons. That cannot be good when you are in opposition," he said.

Opposition front-bench spokesmen Lord Bowness, Lord Pilkington and the Earl of Home quit their posts hours after Lord Fraser announced he was standing down.

William Hague: No deal, but accepting outcome

Baroness Strange announced she was quitting the Tory party for the crossbenches shortly afterwards.

She was joined later on Thursday night by Baroness Flather.

Even the man chosen to replace Viscount Cranborne, Lord Strathclyde, revealed he had offered his resignation before he was asked to take the top job in the Upper House.

John Kampfner: Tories will need convincing that their leader has shown good judgement

And the government has now revealed it is cashing in on the Tory chaos by introducing its Lords reform bill before Christmas - a month earlier than planned.

At the same time Mr Hague faced a barrage of criticism for declaring he would now accept the Labour compromise of Lords reform over which he had sacked Lord Cranborne.

Lord Fraser declared Mr Hague had made a "serious mistake" in sacking Lord Cranborne and there was widespread speculation in Westminster that he had lost his grip of his own party.

The Tory leader hit back, insisting he had the "emphatic support" of his MPs.

William Hague: "If you have to sack somebody of course that doesn't create good publicity"

"We had a serious problem yesterday and I have dealt with that. I am going to rebuild my party on the basis of discipline whether people like that or not," he said.

And, in a bid to regain the political advantage, he wrote to the prime minister accusing him of reversing his position on the abolition of the voting rights of hereditary peers.

Branding it a "staggering U-turn", he said "just because you have abandoned your principles is no reason for me to abandon mine".

Lord Cranborne: Forced out after agreeing secret interim measure on Lords reform

But it was clear that he was struggling to hold onto his credibility with many of his own MPs openly speculating about his future.

Most believe he will be able to remain as leader, if for no other reason than the fact that there is no obvious alternative candidate.

But there is little doubt his leadership has suffered its most serious crisis yet.

The row started after Mr Hague sacked Lord Cranborne after he brokered a deal with the government - without his leader's authority - to keep 91 hereditary peers during the first phase of House of Lords reform.

Lord Fraser: "I regard this as a serious mistake"

Lord Fraser told BBC Radio 5 Live: "The conclusion that he [Lord Cranborne] reached was the right one and I find it in a sense an unnecessary political spat because that is what we wanted to achieve."

The sacking and resignation are the latest twist in an on-going battle between the government and the Tory party on Lords reform.

At present 759 hereditary peers can sit in the Lords. Tory opposition to their abolition had threatened to undermine the government's entire legislative programme.

The new Tory leader in the Lords, Lord Strathclyde, has given his backing to the proposal to keep 91 hereditaries in the interim.

Mr Hague has announced his deputy will be Lord Mackay of Ardbrecknish with Lord Henley as chief whip.