Developers desperate to win one of Gordon Brown’s 10 eco-towns are offering planning consultancies up to £500,000 in no-win, no-fee deals.

At least one of the 15 bidders included on the shortlist, unveiled last Thursday, has made this offer and others are prepared to spend “hundreds of thousands of pounds to secure planning permission”, according to one source.

The hope is that the lavish sums, which will be spent on architects’ fees, sustainability consultancy and legal work, will secure a place in the programme once the 15 is cut to 10 later this year.

A member of the bid team that has made the £500,000 deal with an unnamed planning consultancy, said: “The cash is a real incentive for them. But we pay nothing if we don’t end up as one of the final choices despite the work that ‘s gone into it by the consultancy, and that’s an even bigger incentive.”

The minimum amount of houses to be built for each scheme is 5,000 and the 15 shortlisted bidders were selected from 57 entries. The three largest bids have come from O&H Properties in Bedfordshire (22,000 homes across two sites), Rossington Ecotown Partnership in Yorkshire (15,000 homes) and Pennbury in Leicestershire (12,000-15,000 homes).

The government has set up a panel of experts to advise shortlisted developers on their bids during a three-month consultation process that began last week.