‘‘We are at a turning point in the history of the Liberal party. We can either be seen as a party of tomorrow, a progressive party which believes in taking action on climate change, or we can go backwards.

‘‘The people that are opposing me within the party do not believe in climate change at all. They make John Howard look like a greenie,’’ he said.

‘‘They are turning back the clock and Australians will punish us very, very severely at the next election if these guys have their way and we go to the election as the ‘do nothing on climate change party’ ... we will get thrashed.’’

And he attacked Mr Abbott, criticising him of flip-flopping on emissions trading.

"Tony Abbott is letting down the whole Liberal Party," he said. "There is not a position on the ETS Tony has not held."

Nine other senior Liberals had also defected from key roles by late last night, capping a disastrous week for Mr Turnbull that has virtually ensured his leadership cannot survive.

Sources close to shadow treasurer Joe Hockey left open the option of him being a candidate - but only if Mr Turnbull was not in the field.

Mr Turnbull last night told a news conference he was determined to get the emissions trading legislation through the Senate and that he believed he could muster the seven Liberal votes that were needed.

While the legislation is due for a Senate vote this afternoon, the rebels may try to delay its progress until they can get a change of leader. It was unclear whether Mr Turnbull would have the numbers to gag the debate and push the legislation through.

''We agreed with the Government on this deal,'' he said. ''We must retain our credibility of taking action on climate change.

''And we also must be seen as men and women of our word. We entered into a bargain, there was an offer and there was acceptance.''

He rejected suggestions he could not continue as leader after the mass defections. ''Nothing has changed as far as the leadership is concerned. My leadership was confirmed only yesterday but it is, as John Howard used to say, always something in the gift of the party room.''

Mr Abbott and Senator Minchin jointly confronted Mr Turnbull in his office after question time yesterday. ''Malcolm was unprepared to reconsider,'' Mr Abbott said. ''I could no longer support the Opposition's policy and therefore could no longer be in the shadow cabinet.''

He said his office had had ''an absolute deluge of emails, the phone lines have been in meltdown, with people saying that the Liberal Party would not be doing its job as an Opposition simply to pass this thing without the scrutiny [that] it demands''.

Mr Abbott said he and Senator Minchin had asked Mr Turnbull if the amended bill could be sent to a Senate inquiry and voted on in February. ''We put it to Malcolm that in light of the heavy criticism of industry groups … and in light of the meltdown which is currently taking place within the Liberal Party, that the matter should be reconsidered.''

Senator Minchin and Senator Abetz, the party's leader and deputy leader in the upper house, told Mr Turnbull they would stay in their positions until Parliament rises.

Others who resigned yesterday were Victorian shadow ministers Tony Smith and Sophie Mirabella, lower house Opposition whip Michael Johnson, Senate whip Stephen Parry and deputy Senate whips Judith Adams and David Bushby.

Three shadow parliamentary secretaries - Mitch Fifield, Brett Mason and Mathias Cormann - quit on Wednesday.

Victorian Liberal Petro Georgiou attacked the dissidents. ''The shadow ministers who resigned today because they couldn't accept the party room decision have done the Liberal Party incalculable harm. That harm will be measured by lost votes at the ballot box.''

But Mr Johnson said it was time for Mr Turnbull to go.

''With a heavy heart I do say that … my leader's position is untenable,'' Mr Johnson said. ''He should respect the convention that when senior people have no confidence in the leader, they should quit. He said deputy leader Julie Bishop should ''go and see Malcolm, if she hasn't done so already, and tell him the shadow ministers are against you … This is about her protecting the party's interests for the future. We've had a terribly difficult time.''

Senator Minchin said his resignation was ''in response to a groundswell of opposition from colleagues, the business community and constituents in relation to the position adopted by the Coalition to support the passage of amended legislation over the coming days''.

A prominent climate sceptic, Senator Minchin received a round of applause as he entered a special meeting of Liberal senators last night.

Ms Mirabella said she was prepared to demote herself so she could vote against the flawed legislation, and Senator Abetz said: ''I plead with the leader to accept the party room verdict on this issue.''

Mr Smith said he could not vote for an emissions trading scheme without knowing what the rest of the world was doing. ''You can be fully committed to effectively combating climate change without supporting this ETS at this time,'' Mr Smith said.

Controversial West Australian Wilson Tuckey said: ''At this point in time, the only person that can stop the demise of the Liberal Party is Malcolm Turnbull, and he should resign.''

Key Turnbull ally Michael Ronaldson insisted Mr Turnbull need not blink and said the Coalition could not afford to vote against the legislation. ''For the Coalition to remain relevant, in my view, we must pass this legislation,'' he said.

The manager of Government business in the lower house, Anthony Albanese, said the Government had an agreement with the Opposition for a vote in the Senate at 3.45pm today, followed by a sitting in the House of Representatives on Monday.

With AAP, TOM ARUP, DAN HARRISON

The Age