AA patrol drivers are experiencing long delays in responding to breakdown calls from motorists because the company has not upgraded their laptops, a trade union claimed.

Union group GMB, which represents 1800 employees in the AA, commissioned an independent analysis of laptops following a number of complaints from its members.

Staff employed by the AA told the GMB that the current laptops did not support the sophisticated software applications patrol drivers used, which includes GPS positioning.

The report assessed a single Panasonic CF-28 - the standard laptop used by the AA's fleet - provided anonymously by an AA driver.

"The AA has allowed this solution to be run down and has starved it of investment. The lack of investment also has other serious implications such as on the morale of the AA engineers in the field trying to work with a solution that is unworkable," said the report's author, Constantine Serafirm, MD of Sytems Projects.

"The AA categorically refutes the claims made by the GMB's report," a spokesperson for the AA said. "The AA has seen substantial investments in the business including £37m in IT infrastructure over the last three years, £15m in new fleet and technology."

The AA said that plans worth £9m are "in place" to replace the patrol system. The new system may not be laptop based, it said.

The AA recently announced a £6.2bn merger with Saga, and is expected to launch a massive integration project between the two companies' data systems.