LIB DEM leadership hopeful Norman Lamb will face a party inquiry after his campaigners were accused of subterfuge to undermine his opponent Tim Farron.

Investigators revealed yesterday that members of Mr Lamb’s telephone campaign team had appeared to pose as staffers from Liberal Democrat HQ before asking party members questions that undermined Mr Farron.

A Lib Dem member who received one such call told the Independent on Sunday the telephonist had brought up Mr Farron’s abstention over gay marriage and his support for reducing the time limit on abortion.

Lib Dem membership lists were allegedly used in the operation. If true, this would be a breach of party rules.

“We have been made aware of an alleged breach of party rules and are looking into the issue as a matter of urgency,” said a Liberal Democrat spokesman.

“The Liberal Democrats take any alleged breaches of party rules extremely seriously. The party has contacted both teams to reiterate rules on the leadership process.”

The police and the Information Commissioner’s office have also been dragged into the row by concerned party members.

Push-polling, where a supposedly impartial poll is used to increase support for a particular product or candidate, is most often associated with the right-wing in the US.

In the Republican primaries before the 2000 presidential election, George W Bush’s campaign reportedly asked voters in South Carolina: “Would you be more likely or less likely to vote for John McCain for president if you knew he had fathered an illegitimate black child?”

Mr McCain and his wife had in fact adopted a Bangladeshi girl.