Allen & Overy (A&O) and Clifford Chance (CC) have taken lead roles on one of the largest London lettings deals so far this year.

The magic circle duo have advised as the European Medicines Association (EMA) agreed a pre-let of 250,000 sq ft in a new 20-storey tower which Canary Wharf Group will start building at 25 Churchill Place on the Wharf later this year.

As part of the pre-let deal, EMA will lease the basement, promenade, ground and first nine office floors in the tower. The 25-year lease will start at £46.50 per sq ft, and the EMA has negotiated a 37-month rent free period that it will use to finance the building's fit-out.