Tate Modern in London has welcomed a £50m windfall from the DCMS to help fund its expansion plans.

Secretary of state for culture, media and sport, James Purnell, announced the capital investment – the largest commitment by government for a cultural project since the 1998 opening of the British Library.

Tate director Nicholas Serota said: “This gives us a platform for the creation of an institution for the 21st century, designed to serve the next generation of artists and visitors and confirms London’s position as one of the leading international centres for the visual arts.”

The expansion involves the construction of a 21,000sq m (1,951sq ft) building on the foundation of the former power station’s oil tanks, adjoining the existing art gallery, to increase available space by 60 per cent.