A £7.5m project to renovate secret rooms occupied by Churchill's wartime cabinet gets underway this week.

The project, which was made possible by an eleventh-hour grant of £2m from the National Heritage Memorial Fund, will treble the size of the existing Cabinet War Rooms museum and create public access to rooms hidden for nearly 60 years.

Since 1945 the warren of tiny rooms - for so long the nerve centre of military planning, had been used as a Treasury archive and MoD photographic department. Many original features remain such as bunks, electronic equipment and furniture.

'These inauspicious, yet historically important rooms have been hidden from the public for too long', commented Phil Reed, director of the Cabinet War Rooms.

Phase one of the project will renovate the Churchill family's private quarters including Mrs Churchill's bedroom, private dining room and underground kitchen.

Art education and conference facilities will be created and a 900sq metre space to house a museum dedicated to the life and work of Sir Winston Churchill.

Building work will be completed in July 2002 and the rooms will open to the public during spring 2003.

Phase two, costing a further £5m (yet to be secured) will see the design and fit-out of the Churchill museum. The museum is scheduled to open in 2005 to coincide with the 60th anniversary of VE day and the 40th anniversary of Sir Winston's death.