Solicitors have been warned they risk running out of time if they delay registering for the extended online claims portal.
From 31 July employers' and public liability claims will be brought into the RTA Portal with fixed fees for practitioners in those areas.
The Gazette understands a significant number of firms affected have yet to register that they intend to use the revised claims portal.
The company running the scheme today warned that leaving registration until the last minute may mean the account is not up and running for the end of July.
Tim Wallis, chairman of Claims Portal Ltd, said the process had been open for more than a month and firms that are late could experience a logjam and subsequent delay.
'We've built the lake, filled it with water, put up directions in bright flashing lights - but we can't force them to drink,' he said.
Those who need to register will have to understand the government's new protocol and the portal account and agree the practical detail of how claims will be handled.
To help organisations, Claims Portal Ltd has provided information on its website, including a guide to set-up options and answers to common questions, as well as walk-throughs showing what the portal looks like and how it works.
Meanwhile, the government has confirmed the Civil Procedure Rules Committee will meet on Friday to decide the rules over the extension of the fixed-fee portal to employer and public liability claims. The rules will then go to ministers at the Ministry of Justice for agreement.
The extension is still due to come into force on 31 July, and solicitors have expressed concern there is too little time for firms to adjust to new rules.
David Greene, senior partner at London firm Edwin Coe, and president of the London Solicitors Litigation Association, said that officers at the MoJ were doing their utmost to meet the deadline but that the timetable would disadvantage lawyers using the scheme.
'The changes to take effect in less than a month extend the portal to a wide range of work of a solicitor's practice. They will have a significant effect on a practice but without draft rules it is difficult for practitioners to prepare. The devil will be in the detail,' he said.
'This squeeze on time for implementation or consultation on major changes seems to be becoming a normal approach in civil and crime. It is simply an unacceptable way to conduct change and is grossly unfair for practitioners and the public.'