HOLLYWOOD stars have been in Oxford filming what could be next summer’s blockbuster smash.

Stars working on prequel X-Men: First Class are shooting scenes at the Sheldonian Theatre in Broad Street.

James McAvoy and Troy star Rose Byrne are among those who have been spotted relaxing between filming and braving the English weather.

The franchise is one of the most successful in Hollywood history, with the four previous films grossing more than $1.5bn worldwide since 2000.

Last night, the city council said attracting major movie crews to the city helps boost visitor numbers.

Spokesman Fiona Colcutt said: “We are always pleased when the heritage of Oxford is recognised, boosting the profile of Oxford and attracting more visitors.”

Scottish actor McAvoy, 31, is best known for his roles in Atonement, The Last King of Scotland and The Lion, the Witch and the Wardrobe.

Rose Byrne, 31, has starred in 28 Weeks Later and Sunshine.

Kevin Bacon is also in the cast, as well as Skins and About a Boy star Nicholas Hoult, and Mad Men actress January Jones.

The crew has set up a base camp in Christ Church Meadow and ‘X-Men Crew Only’ food vans have been set up in Radcliffe Square.

Filming started on Wednesday and was expected to last two days.

One onlooker said: “I couldn’t believe my eyes. These top actors were just hanging around the Sheldonian.”

Previous X-Men films have starred Hugh Jackman, Halle Berry, Sir Ian McKellan and Sir Patrick Stewart, who lives in Great Tew.