Major upheaval of the personal injury sector is happening too quickly and without evidence to support it, according to the government’s own adviser on the subject.

Professor Paul Fenn, who spent a year studying the RTA Portal for a report released in June, this week warned of ‘significant risks’ posed by the Ministry of Justice’s proposals.

Ministers want to extend the portal to cover RTA cases worth up to £25,000 plus employer and public liability cases. Fixed fees will come in for each type and value of claim, with costs for the lowest-value RTA claims falling from £1,200 to £500.

Fenn said the portal had achieved some success in reducing costs and delay, but without more evidence it was too soon to extend its remit.

‘There first needs to be a thorough assessment of the likely impact of the proposed level and structure of fixed costs on the way the market works and the extent to which this may have an effect on the number of accidents and claims, as well as damages,’ he said.

Fenn warned the new costs mean the defendant’s reward for admission of liability would be too high, creating a de facto no-fault scheme and increasing the number of claims.

The Law Society has written to justice secretary Chris Grayling asking for a delay to the 1 April date for implementing the changes.

A dedicated email address (insidetrack@lawsociety.org.uk) has also been created for personal injury solicitors to offer evidence before the MoJ’s 4 January deadline for responses to a consultation. Law Society president Lucy Scott-Moncrieff described the proposals as ‘simply misconceived’. Around 3,500 people have signed an e-petition calling for a U-turn on the plans.