The resignations of Senators Cormann,Fifield and Cash are a mortal blow for Mr Turnbull,who has now lost the support of up to 10 members of his cabinet.
"It's with great sadness and a heavy heart that we went to see the Prime Minister yesterday afternoon to advise him that in our judgement he no longer enjoyed the support of the majority of members in the Liberal Party party room,"said Senator Cormann.
Mr Dutton,the former home affairs minister,has asked for the Prime Minister to call an immediate party room meeting for Thursday to resolve the leadership crisis.
"Earlier this morning I called the Prime Minister to advise him that it was my judgement that the majority of the party room no longer supported his leadership,"he said.
"As such,I asked him to convene a meeting of the Liberal Party at which I would challenge for the leadership of the parliamentary Liberal Party".