The cost of work done by law firms advising the Mayor of London’s economic development agency is to be scrutinised by the London Assembly, the Gazette has learned.

The news emerged after Boris Johnson answered questions on the amount that the London Development Agency (LDA) paid to law firms for advice on the Olympic Park project.

Len Duvall, London Assembly member for Greenwich and Lewisham, will ask Johnson how much the LDA has spent on advice from its panel law firms since he became mayor in May 2008.

The new legal spending probe represents a broadening of the Olympic Park spending inquiry, which was initiated after the LDA admitted to a £160m budget overrun on the project in September. Duvall subsequently questioned the mayor on the work done by law firms which gave advice on the project, and how much they were paid.

Responding last week, Johnson pointed to the ‘complexity’ of the Olympic land acquisition process and said that due diligence work carried out by Eversheds and DLA Piper ‘covered all aspects of the land assembly and the related commercial transactions on the Olympic Park’. The firms were paid £230,000 in total, which Johnson said was ‘an effective and efficient use of resources.’

A report prepared for an LDA board meeting in September noted that the LDA’s in-house legal resources had to be ‘enhanced’ over the last year ‘to provide more consistent input to commercial matters with greater control over the use of external firms’.

The LDA’s current law firm panel comprises south-west firms Ashfords and Burges Salmon; City and national firms DLA Piper and Eversheds; City firms Herbert Smith, Lovells and Stephenson Harwood; and Scottish firm Shepherd & Wedderburn.