Matrix Chambers' Thomas Linden QC has taken on the lead role for Commerzbank on its high-profile €50m (£41m) bankers' bonuses case, following Jonathan Sumption QC's elevation to the Supreme Court.

The closely-watched case is set to go to trial later this month, with Sumption QC no longer involved due to his appointment as a Supreme Court justice.

The hearing date is set for 23 January, with a running time of four weeks in the High Court.

The case, which was first filed with the High Court in September 2009, has seen 104 bankers bring claims against Commerzbank, following a 90% bonus cut announced after it merged with Dresdner Bank in May 2009.

Before the takeover, Dresdner staff were informed that a €400m (£330m) pot had been put aside to cover bonus expenses. However, after the tie-up, the bank sent out an email saying that bonuses would be reduced. The dispute rests on Commerzbank's assertion that the decision over bonus was discretionary.

Linden is leading for Commerzbank with Brick Court's Martin Chamberlain and Oliver Jones and Linklaters employment partner Nicola Rabson.

In March last year the bank failed in an attempt to get the case dismissed on a summary basis.

Sumption, who was formerly advising Commerzbank alongside Rabson, is due to be formally sworn in at the Supreme Court today (11 January).

Meanwhile, 4 Pump Court's Nigel Tozzi QC and Kate Livesey are leading for 83 of the bankers, alongside Stewarts Law commercial litigation partner Andrew Shaw and commercial litigation head Clive Zietman.

Essex Court's Andrew Hochhauser QC and David Craig have been instructed to lead for the remaining 21 bankers, alongside Mishcon de Reya employment partner Mark Levine.

Zietman said: "This is a case about English contract and employment law. Although there has been much commentary about its political and commercial significance, it remains a case that will be decided by the courts on basic English legal principles and nothing else."

Mr Justice Owen has been assigned to hear the case in the Queen's Bench Division.