Tensions escalated, with accusations that Mr Abbott endorsed chief whip Warren Entsch's plan to send the email. Supporters of Mr Hockey have confirmed that he warned Mr Entsch the email would further destabilise the party and unnecessarily aggravate tensions between Mr Turnbull and Mr Abbott. A source said Mr Pyne - a long-time supporter of Mr Abbott - warned against sending the rebuke to MPs, predicting the contents would leak immediately. Mr Pyne refused to comment on whether he aired such views to his leader. Mr Entsch's initial denial that the email was sent with Mr Abbott's knowledge crumbled less than 24 hours after the statement was delivered last Wednesday. He made an embarrassing retreat and admitted the Opposition Leader was presented with a copy of the message shortly before it was dispatched. But The Sun-Herald can reveal a parliamentary steward ferried the draft version of the email to Mr Abbott before the end of question time. The remaining members of the leadership group - Mr Pyne, Mr Hockey and Ms Bishop - quickly became aware of its contents. Mr Pyne and Mr Abbott examined the document before Mr Abbott walked the piece of paper to his chief of staff, Peta Credlin, who was seated in the Opposition Leader's adviser's box. Now that it had Mr Abbott's apparent approval, Mr Hockey attempted to warn Mr Entsch against sending it - minutes before the email arrived in inboxes across Parliament House.

Mr Abbott has refused to confirm whether he authorised the email but has defended its message, saying it was ''not about any particular individual''. Mr Hockey was the favourite in a three-cornered leadership contest in November 2009, but he lost out when Mr Abbott deposed the then leader, Mr Turnbull, by only one vote. A source said the once-fractured relationship between Mr Turnbull and Mr Hockey had improved significantly in recent months. ''Tony has an unreasonable paranoia about Malcolm's standing in the party and it is aggravated by the healing of the rift between Joe and Malcolm,'' the source said. ''But in reality, Malcolm has been caught up reasonably unfairly in this mess and pretty much blindsided by the whole thing.'' The Liberals have been rattled by disunity for the past week. On Tuesday, Mr Abbott implored his party room not to fritter away its thumping lead in the polls, describing public support as ''fleeting and ephemeral''. Mr Abbott's plea was seen as an attempt to quell disquiet after last week's Sun-Herald revealed the details of a heated telephone clash between the Opposition Leader and Mr Hockey. Mr Hockey accused Mr Abbott of leaving him ''swinging in the wind'' over family trust tax arrangements.

Mr Hockey was forced to retreat from comments he had made after the National Party made it known it would not stand for any amendments to the status quo, which delivers favourable tax conditions to rural and regional voters. Mr Hockey also took Mr Abbott to task over the party's need to ''stand for something'' and deliver firm and clear policy outlines. The tensions deepened when it was revealed that party elder and factional hard man Nick Minchin had criticised Mr Abbott's ''small target'' strategy, urging him to adopt strong policy positions rather than play populist politics. Long-time loyalists of Mr Turnbull are convinced the email was not only endorsed by Mr Abbott but that its contents were devised by him and his office - a charge hotly denied by Mr Abbott's senior staff. Mr Turnbull had said: ''When you send a letter or email to every member of the government, or the Coalition, the reality is the chances of it finding its way into the hands of the press are extremely high.''

One MP expressed his disgust with the decision of the four other party whips to sign the email without realising the damage it would cause. It is understood there are a number of backbenchers who are furious about Mr Abbott's continuing refusal to promote from the younger ranks.