Henley MP Boris Johnson claimed the problem of Oxfordshire police officers jumping ship to join the better-paid Metropolitan force had largely been resolved - only to be contradicted by Thames Valley Police.

The Tory candidate for London Mayor, appearing before the Commons Home Affairs Committee as part of its inquiry into policing, was challenged to say whether he still supported attempts to curb the loss of officers to the Met, or whether his priorities were now with the capital.

The MP, who faces Mayor Ken Livingstone in a London-wide poll on May 1, said: "As far as I'm aware the problems have been considerably ameliorated and I'm happy to say I support and encourage the recruitment of police officers in both areas."

But Thames Valley Police told the Oxford Mail it was still lobbying the Government for help to retain officers. Since last April as many as 100 officers had transferred out of the force, of which 66 went to the Met.

Chief Constable Sara Thornton said: "We are working very closely with Thames Valley Police Authority to try ro persuade ministers, the Home Office and national negotiators that we should be able to pay an increased South East allowance to reflect the cost of living in the Thames Valley."

Earlier this year Andrew Smith, Labour MP for Oxford East, also waded into the row over the disparity in pay. He said: "It is unacceptable that the gap in allowances with the Metropolitan police is widening, and that they actively poach officers Thames Valley has trained."

It also emerged in January how money was available to honour a police pay rise for Oxfordshire's officers, but will go directly to the force's reserves instead. The Home Office has ordered forces only to back date officers' 2.5 per cent pay rise to the start of December instead of September.

Thames Valley Police budgeted for the wage payments, but instead the money will be placed in Thame Valley Police Authority's reserves until next year.