Polls say Mandelson is a vote-loser

n Tory focus groups name him most disliked minister n 'Who is deputy PM?' asks Redwood n Threat from Scottish scandals

Peter Mandelson, the "petulant" Minister without Portfolio, has emerged as a voter turn-off in private Conservative Party opinion surveys.

Focus groups of former supporters and uncommitted voters brought together in private by the Conservatives suggest that Mr Mandelson - who has dramatically raised his personal profile during the Prime Minister's holiday in Tuscany - is the most disliked member of the Government.

The political damage could spread to Tony Blair himself, who is seen as weak by some because he is "perceived to be manipulated by spin doctors".

The Tory high command stepped up its attack on Labour's chief spin doctor yesterday - Labour's 100th day in power - identifying him as the weak link in Mr Blair's administration.

"New Labour's first 100 days have identified the weak link in the Labour Government," said John Redwood, the Shadow Trade Secretary. "Peter Mandelson is perceived by much of the public as running the Government, and our focus group evidence shows the public dislike his tactics and his refusal to answer legitimate questions.

"There is a very clear public issue about who is the Deputy Prime Minister; is it Mr Mandelson, who is charged with the news management of the Government, or is it Mr Prescott, who formally holds the title? The question of who holds power while Mr Blair is in Tuscany is now the central political issue for the Government."

In a letter to Tory activists, William Hague, the Opposition leader, attacked New Labour for playing fast and loose with the rules. "Protected by a huge majority, ministers think they can do whatever they want," he said, adding in a clear reference to Mr Mandelson: "They have sought to manipulate the media to hide embarrassing stories about themselves."

The Tories will renew their onslaught on Mr Mandelson this week, accusing him of "high-handed bossiness that has come to typify the New Labour Government".

The Minister without Portfolio anticipated his critics in an interview with the Guardian yesterday: "The Tories are trying to destroy me because I'm a threat to the Tory party." He also said if he was accused of "trying to create the truth" he would plead guilty.

Mr Mandelson, whose caustic treatment of media interviewers triggered a fresh set of negative front-page headlines yesterday, and attracted the "petulant" label from both Tories and Liberal Democrats, is set to defy his critics further with a statement of his political "vision" this week.

He will deliver a Fabian Society lecture setting out his ideas for the future, urging more of the modernisation that has brought the Labour Party into the centre of British politics and made it friendly to business. He also appears on BBC1's Breakfast With Frost programme this morning.

A Conservative source claimed that Mr Mandelson's merciless handling of interviewers prompted a record number of protest calls from Labour voters to Central Office last Friday. "Time and again, they made the same point, 'We voted for Mr Blair, not Mr Mandelson. Why then is he in charge?' " the source said.

While the Mandelson row rages, Labour is seeking to close down the scandal in west Scotland caused by the suicide of Gordon McMaster, MP for Paisley South, two weeks ago.

Nick Brown, the Chief Whip, will take the unprecedented step of visiting Renfrewshire over the next few days to investigate the causes and circumstances of his death, and allegations of "rumour-mongering" in the party and at Westminster about the MP's illness and his sex life.

His inquiry will be in two parts. The first, into the causes of Mr McMaster's suicide, will be complete in time forMr Blair's return this month.

The second inquiry will examine Labour and public life in Renfrewshire. It may be conducted jointly by the Chief Whip and the party's National Executive Committee. It will look into allegations of irregular recruitment practices and the "packing" of selection meetings in Paisley.

Focus, page 15