Award-winning author Philip Pullman has given an Oxford theatre a £100,000 cash injection which means a £6.3m revamp can start next year.

Mr Pullman, author of the His Dark Materials trilogy, is patron of the Pegasus Theatre, in Magdalen Road, and his support was the biggest private donation to the fundraising campaign.

The author, who lives just outside Oxford, said: "I have always supported the theatre and it has always been a source of interesting things and a place to take children.

"The plans are tremendously exciting and this is the time for everyone to pitch in and really help them get the last bit of money they need to get the new build."

Plans to demolish the buildings surrounding the theatre have been in the pipeline for more than 10 years and work had originally been planned to start in April 2008.

But by January only £4.7m had been raised and it was decided to put the plans on hold for a year.

Now, the total stands at just under £5.5m, allowing organisers to start contracting out demolition work for the new year.

Pegasus artistic director and chief executive Euton Daley said: "That Philip should be the first to make such a big gift is so apt.

"He has been one of the most vocal and encouraging supporters of Pegasus.

"We are also getting a lot of support from our youth theatre members and their families as well as the local community.

"With their help, things are really taking off and it is wonderful to have reached this place in the campaign and see light at the end of the tunnel."

Since January, as well as Mr Pullman and his wife Jude's donation, the Garfield Weston Foundation has contributed £100,000 to the campaign and major sponsor Arts Council England, which had already pledged £3m, added another £500,000 to its funding.

A further £100,000 was raised with help from the community, parents' fundraising events, and small grants from trusts.

Oxford City Council has supported the scheme to the tune of £271,000 and Oxfordshire County Council has pledged £1.2m.

About 1,500 young people get involved with workshops and theatre sessions at Pegasus theatre each year, many through Oxford Youth Theatre.

Among them are James Roberts, 14, from Kennington, and Milo Hynes, nine, from East Oxford.

James said: "It's really good news, once they have the refurb it is going to be a lot better than it already is and it is already a very good standard.

Milo said: "It's really cool. Pegasus is great fun and I am looking forward to the new things we will be able to do."