Oxford City Council has been accused of covering up a traffic report because it did not like what it was being told.

The authority paid transport expert Peter Headicar £2,500 to give a commentary on how the city’s housing and jobs plans would affect Oxford’s roads over the coming decades.

But Mr Headicar’s findings were heavily critical of the Northern Gateway business park development proposed near Pear Tree Roundabout, part of which would be on council-owned land.

The report was shelved by city planners and not released to the public.

City council spokesman Louisa Dean denied last night that the authority had not published the report simply because it was negative about the Northern Gateway.

Mr Headicar’s work, completed in 2009, only came to light after a Freedom of Information request from campaigners fighting the Gateway scheme.

His report said the development, for 3,000 jobs and 200 homes, would bring gridlock to the north of the city.

Engage Oxford, the group that uncovered the report, invited Mr Headicar to present his findings to the public inquiry on the council’s core strategy this week.

The core strategy, which contains plans for 8,000 city homes along with the Northern Gateway business park, will be the planning blueprint for the city until 2026.

Mr Headicar told the hearing the Gateway project was the “outstanding negative” of the council’s plan and would generate an extra 1,000 car journeys a day.

He said traffic would increase by 51 per cent by 2026 even if there was no development in the city and, since he completed his report, government funding for major road improvements had been thrown into jeopardy.

Mr Headicar, a reader in transport planning at Oxford Brookes University, said: “The core strategy, in my view, does not provide demonstrable evidence that the development can be achieved without substantially worsening conditions.”

He told the Oxford Mail he believed the city council would welcome some of his findings because they would have supported its case for building thousands of homes near Grenoble Road.

Government planning policy changes have now ruled that development out.

Mr Headicar said he thought the council had not reckoned on his professional analysis questioning the Gateway development.

He said: “I was critical of the Northern Gateway site and I don’t think they had anticipated that.

“My hunch would be they did not publish something that was critical.”

At the public examination, Oxford City Council’s spatial strategy and economic development manager Mark Jaggard confirmed Mr Headicar had been commissioned by the authority to write the transport commentary.

He said there had been a “difference of opinions” and the work had a “long, torturous history”.

Mr Jaggard added: “It did not seem helpful and worthwhile publishing it.”

Council spokesman Louisa Dean said: “The opinions expressed are from a transport perspective only. As it was only from a transport perspective and not part of the research used to prepare the plan we chose not to publish it.”

The inquiry into the core strategy ended yesterday. Government planning inspector Stephen Pratt is due to publish his findings this autumn.