DAVID Cameron yesterday continued his political gamble by placing more capital behind his beleaguered Culture Secretary, who is just days away from giving evidence over his role in the BSkyB takeover bid that could break his career.

The Prime Minister publicly insisted he had no regrets in handing Jeremy Hunt oversight on Rupert Murdoch's failed £8billion attempt to win full control of the broadcaster.

Mr Hunt is due to appear before the Leveson Inquiry on press standards next Thursday.

Should the Secretary of State fail to convince, Mr Cameron –instead of relaxing over the Jubilee weekend – could find himself reshuffling his Cabinet. With the London Olympics just weeks away, Westminster insiders are predicting Hugh Robertson, the sports minister, could be promoted to the Cabinet to provide continuity.

Next week, the heat on Mr Cameron is set to intensify with those scheduled to appear at the inquiry including Cabinet ministers Theresa May, Michael Gove, Ken Clarke and Vince Cable, the Business Secretary who lost quasi-judicial oversight of the BSkyB bid after he said he had "declared war" on Mr Murdoch.

Tony Blair, the former prime minister, who courted the News Corporation owner while in office, is due to give evidence on Monday.

Yesterday, Mr Cameron again stood by his Culture Secretary, saying: "I don't regret giving the job to Jeremy Hunt. It was the right thing to do in the circumstances - The crucial point, the really crucial point, is did Jeremy Hunt carry out his role properly with respect to BSkyB and I believe that he did."

He added: "Some people are saying there was some great conspiracy between me and Rupert Murdoch to do some big deal to back them in return for support. Rupert Murdoch has said that's not true, James Murdoch has said that's not true, I have said that's not true. There was no great conspiracy."

This week it emerged that Mr Hunt had sent the PM a memo, making clear his strong support for the News Corp bid. A month later, following Mr Cable's outspoken remarks, Mr Cameron put the Culture Secretary in charge of determining whether or not to approve the bid.

Last night, Harriet Harman, Labour's deputy leader and the shadow culture secretary, said: "David Cameron might think that he can brazenly say, 'No regrets' and this will somehow draw a line under it, but people will not accept that.

"It was evident that he gave the decision on the Murdoch bid to Jeremy Hunt when he knew Jeremy Hunt was not impartially judging the bid but was in favour of the bid."

Earlier at the Leveson Inquiry, Adam Smith, Mr Hunt's former aide, said his boss had told him to quit after emails revealing the close relationship between the Culture Department and News Corp were released.

Mr Smith, 30, said that on the evening the documents were published, the Culture Secretary reassured him that he had only been doing his job and not to worry. But the following day Mr Hunt spent the morning in meetings before calling in Mr Smith and telling him: "Everyone here thinks you need to go."

Mr Smith conceded that he had been "too flippant" in the text messages and email exchanges with News Corp lobbyist Fred Michel.

"In hindsight, the tone of the language that I used was not appropriate," he said.

Jonathan Stephens, Permanent Secretary at the Culture Department, said Mr Smith had, against his will, been "drawn into almost what seems to me to be a sort of web of manipulation and exaggeration, and was drawn inadvertently beyond what he intended to do or what he wanted to do".