Jude Law and Helen McCrory join topping out at the Young Vic

Jude Law, Helen McCrory and architect Steve Tompkins

The ceremony marks the new theatre reaching its full height, with completion expected in Autumn 2006.

"It's a thrilling moment for us and for British theatre," said artistic director David Lan. "It means that the world-renowned Young Vic auditorium and company are not just of the past and of the present but of the future."

The substantial grant from the LDA leaves the campaign with only £600,000 left to raise to secure the future of the company.