Coughlin and Cherie Booth look to sue RBSCalifornia-based Coughlin Stoia Geller Rudman & Robbins has instructed Cherie Booth QC of Matrix Chambers to investigate whether two UK local authorities can lead a US class action against the Royal Bank of Scotland (RBS).

The firm has made an application in the US courts to become the lead team on a US class action, which it intends to open to US and European investors who lost money in RBS.

Coughlin Stoia founding partner Patrick Daniels met with North Yorkshire and Merseyside councils earlier this month to discuss whether they could join the US action. Together the local authorities combined council pension funds are worth £4bn, but their deficits are believed to have grown significantly thanks to the large investments they made in RBS.

The claim alleges that the local authorities were reassured that their investments were safe by former RBS chief executive Sir Fred Goodwin. It names Goodwin and the entire RBS board of directors, including former chairman Sir Tom McKillop, as defendants.

It is the first case of its kind to be mooted in the UK. It is understood that initially Booth will be working for the UK investors interested in joining the US action, while Coughlin Stoia gathers evidence from US investors.

So far a Dutch metal workers team had joined the action.

If the lawyers are successful in getting the case off the ground, it could end up being the largest global class action ever brought.