Labour has accused the Tories of breaching political funding rules after a gaffe by David Cameron over his party's secretive campaigning headquarters in the Midlands.
John Hutton, the Work and Pensions Secretary, called for an urgent investigation into the centre run from a West Midlands manor house by an organisation called Constituency Campaigning Services (CCS). The CCS receives£1m a year from the Midlands Industrial Council (MIC), a body which has been used by business people to donate sums totalling almost £1m to the Conservatives without their identities being revealed.
A key mover behind the MIC is reported to be the car importer Robert Edmiston, named yesterday as the owner of the CCS's base, Coleshill Manor.
The row followed remarks by Mr Cameron on BBC1's Sunday AM when he said the CCS was "effectively part of the Conservative Party". Labour said that put the Tory party outside of electoral rules.
The Tories have declared the CCS as a separate body. Last night the party issued a statement denying it had broken the rules. It said the CCS was independent of the Conservative Party and was properly registered with the Electoral Commission.
Mr Cameron also confirmed in the interview that he had met the members of the MIC, which he said was "an organisation that raises money from businesspeople". He added: "Where those people are specifically giving money to the Conservative Party, they declare it in the right way."
Electoral Commission rules state that membership associations registered as regulated donees cannot be part of a political party.
Mr Hutton said Mr Cameron had contradicted his party's own statement and confirmed that the centre was part of the Conservative Party. He added: "The centre is funded as a regulated donee, yet under the law regulated donees cannot be part of a political party." He called for Mr Cameron to name his "secret backers".
Labour has named 12 businessmen who donated nearly £14m, but so far the Tories have refused to name all their lenders.