Slaughter and May’s French ally Bredin Prat has launched a tax practice after hiring a six-lawyer team from Paris tax leader CMS Bureau Francis Lefebvre (BFL) – plunging the two French firms’ long-standing referral links into doubt.

The high-profile group started at Bredin Prat on 4 November and the defection is a major blow for BFL as the senior departing lawyer, partner Renaud Streichenberger, is regarded as one of France’s top tax lawyers.