SCOTLAND YARD detectives who are investigating the cash for honours scandal have uncovered a private meeting held last summer at which key Downing Street aides allegedly plotted a cover-up.

The meeting was attended by four of Tony Blair’s closest aides, including Jonathan Powell, his chief of staff, Lord Levy, Labour’s chief fundraiser, and Ruth Turner, a senior adviser.

It is understood that Levy was questioned about a note of the meeting, said to have been held at Downing Street, when he was arrested last week for allegedly conspiring to pervert the course of justice. One source described the note as setting out an “action plan” for dealing with the police inquiry.

According to a senior Whitehall source, police believe they now have evidence to recommend charges in the investigation. “They (the police) believe there was a conspiracy to cover up evidence over a period of weeks,” said the source yesterday.

The disclosure of the meeting — also attended by John McTernan, director of political operations — will add to mounting pressure on the prime minister to leave office early.

Jon Cruddas, a contender for the Labour deputy leadership, in his appearance today on BBC1’s The Politics Show, will call on Blair to step down. In a live interview on Sky News, Charles Clarke, the former home secretary, is expected to launch a fresh salvo against Blair by declaring that Labour has sunk to its “worst position for 20 years”.

A Sunday Times survey of Labour backbenchers revealed that 20 out of 39 say Blair is an electoral liability and four of these say he should step down now. A further seven called on him to step down in time for the May local elections. Nine backbenchers said he should go if charges are laid.

Blair is understood to have been “copied in” to the note of the meeting. However, the police have not yet established whether he was present during the discussions.

The key meeting, which is not thought to have been attended by lawyers, is understood to have been held early last summer after the first arrest in the cash for honours investigation.

On June 20, 2006, Sir Gulam Noon, who lent Labour £250,000 and was nominated for a peerage, was invited to Downing Street for a private meeting with Blair.

Noon had previously accused a senior Labour figure, later identified as Levy, of asking him to withhold details of his loan from parliamentary watchdogs. Noon, who has not been arrested, has been interviewed under caution by police.

Yesterday Noon declined to comment on what was discussed at his meeting with Blair or whether it had been arranged by Turner.

At least two of the other lenders nominated for peerages — Sir David Garrard and Barry Townsley — received handwritten notes from the prime minister.

Detectives suspect that crucial e-mails and other documents were initially withheld by Downing Street although No 10 has strenuously denied that it failed to co-operate.

According to the source, a note of the “cover-up” meeting was presented to Levy by police after his arrest last Tuesday. He is understood to have declined to comment on that meeting and on the note — or any of the other questions put to him — during the four-hour police interview. It was Levy’s second arrest and his fourth interview under caution.

A spokesman for Levy declined to comment on any of the meetings. However, he added that the peer “completely denies any allegations of wrongdoing whatsoever”.

All four aides have been interviewed under caution in the past three weeks. Levy was arrested on suspicion of “conspiring” to pervert the course of justice. Turner was arrested on suspicion of perverting the course of justice — not of conspiring to do so with others.

Powell and McTernan were interviewed under caution in the week before Turner’s arrest.

The police inquiry was launched after The Sunday Times revealed that Labour had secretly funded the last election with a series of loans from wealthy businessman.

Four of those men who lent money were subsequently recommended for peerages by Blair.

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