Desai called on the owner to do more to secure the site.

He said: “It’s Preston’s legacy.

“We’ve tried really hard to get them to secure the building so this damage doesn’t happen, but they don’t seem to be succeeding.

“There is a hole in the board to cover the windows and children can climb through it.”

Much of the site is earmarked for demolition and owners Zimrock Ltd said contractors were on site and ready to begin work.

A Zimrock Ltd spokesperson said: “There is 24-hour security on site and we have done what we can.

“There are billboards around the site, but if anyone is determined to get in, they will.”

The orphanage opened in 1872 and was funded by a wealthy local widow.

It was run by nuns and part of the site became a hospital known as Mount Street Hospital.

The orphanage closed in 1954 and the hospital on the site in 1982.