A Labour motion calling for the Culture Secretary to be referred to the independent adviser on ministerial standards has been defeated.
MPs voted 290-252 against an investigation into the way Jeremy Hunt handled the BSkyB bid, giving the Government a majority of 38.
It followed a Commons debate in which MPs questioned whether Mr Hunt should be investigated for allegedly breaching the ministerial code in his handling of News Corp's attempt to take full control of BSkyB.
Nick Clegg called on Liberal Democrat MPs to abstain from the vote, although he does want David Cameron to launch an investigation into the Culture Secretary's conduct.
The Deputy Prime Minister has repeatedly told the Prime Minister the case should be looked at by Sir Alex Allan, the independent adviser on ministerial interests.
Despite this, the Lib Dem leader gave his strongest backing yet for Mr Hunt during his appearance at the Leveson Inquiry, saying he believed the Tory minister had given a "full, good and convincing account" of his involvement in the bidding process.
Mr Cameron also backed Mr Hunt during Prime Minister's Questions , telling the House that Sir Alex had told him in a letter the adviser felt he could not "usefully add" to the case.
But the opposition motion called for Sir Alex to consider whether Mr Hunt misled Parliament and failed to take responsibility for his special adviser Adam Smith.
Mr Smith resigned after admitting his contacts with News Corporation had been too close.
Deputy Labour leader Harriet Harman told MPs during the debate: "There is prima facie evidence that the Secretary of State failed to give accurate and truthful information to the House.
"At the very least, there is prima facie evidence that the Secretary of State failed to take responsibility for the management and conduct of his special adviser."
She went on: "I strongly urge honourable members from all sides of the House to reflect on this, to support the rights of the House, to reinforce the importance of the ministerial code and vote in support of this motion.
But Mr Hunt, defending himself against the allegations, said: "I have taken more trouble and published more information than probably any other government has published in any previous bids. I made huge efforts to be transparent."
He added: "I wish to draw the House's attention to the very important distinction between inadvertently misleading this House and lying.
"Lying is something that implies deliberate intent... I have spent six weeks being accountable for my actions and being proved right."
The Lib Dem decision to abstain was said to have received "unanimous support" at a meeting of the parliamentary party on Tuesday night.
It was the second time they have abstained in mass from a Commons vote while in government - the first related to Mr Cameron's use of a veto at an EU summit.
Lib Dem spokesman Don Foster told Sky News: "Nick Clegg is very firmly of the view that other questions, particularly in relation to the ministerial code, still remain and these should have been appropriately investigated.
"[That's] why he has not supported the Prime Minister on this occasion."
Mr Clegg is reported to have discussed the matter with Mr Cameron on a number of occasions over recent weeks, and to have told him the Culture Secretary should be subject to a probe.
Evidence of the coalition split will intensify pressure on the Prime Minister to call in Sir Alex for an independent assessment of whether the ministerial code has been breached.
He is facing accusations of double standards after calling an investigation into Tory chairman Baroness Warsi , who has admitted failing to declare business links with a relative who accompanied her on an official trip to Pakistan.
