Best-selling author Philippa Gregory has joined the fight to save Barnet Museum.

The author of The Other Boleyn Girl agreed to sign the petition to save the museum, and to write to Boris Johnson, after being contacted by Mill Hill mother Julie Tucker.

Ms Tucker has been campaigning to save the museum, in Wood Street, since her daughter’s class at Goodwyn School, Hammers Lane, went on a trip there in January.

Ms Tucker is an avid reader of Ms Gregory’s novels and contacted her via her Facebook page after she noticed that Ms Gregory has written about the Battle of Barnet, which is featured by the museum.

Ms Gregory signed the online petition and wrote: “As a historian and international best-selling author I was shocked to hear of the museum’s problems from one of my readers.

“I urge councillors to support the continued use of the building by the museum team.

“It offers an invaluable insight into local history which should be celebrated not forgotten.”

Since appearing on Philippa Gregory’s Facebook fan page the petition has gone global with signatures being added from Austria, India, Australia, Canada and Spain, making a total of 9,294 names to date.

Barnet Museum is run by a team of volunteers but is under threat because of council plans to charge the museum market rate rent which the organisation cannot afford.

Campaigners hope that the council will agree to offer the museum peppercorn rent to enable it to survive.

Mike Noronha, museum treasurer, said: “It would be a tragedy to lose this vital community asset which is so valued not only by the people of Barnet but, as we have seen from the online petition, much much further afield.

“The support of Philippa Gregory is truly appreciated and will hopefully help to persuade the decision makers that this is a valuable and irreplaceable community and national resource, with visitors coming from far and wide.”

Philippa Gregory is a historian and writer who writes novels set in the Tudor period.

She wrote The Other Boleyn Girl which was made into a TV drama and a major film.