Windsor's iconic 17th century Guildhall has been allowed to become 'shockingly dilapidated' by the Royal Borough warns the town's leading conservation society.

The Windsor and Eton Society was established after the war to keep an eye on the town's historic buildings.

Now a letter written by its chairman - former mayoress Margaret Lenton, vice-chairman Chris Aitken and heritage committee chairman Anne Taylor is accusing the council of ignoring an officers' report that warned water had been leaking through its first floor windows since 2017.

The report warned that the loss of the windows would damage the historic fabric of the building. But the society's letter says the report was ignored and that the windows may now be beyond repair.

The society says: "They have now been knowingly left to deteriorate by the Royal Borough for over three years."

It accuses the authority of a 'a breach of duty, or at the very least, negligence.'

Speaking to the Observer this week Mr Aitken said: "The windows are just an example of a missing strategy.

"There has been no previous conservation study of the Guildhall out of which would flow a timed maintenance plan.

"Maintenance has only been done on an 'immediate needs' basis where a problem becomes visible.

"We are a bit out of patience with the council."

The Royal Borough's deputy leader Cllr Samantha Rayner said the letter from the Windsor and Eton Society had been received by the council and that she had sent it to the property team to respond and investigate.

She said: "The only other comment is that last year the council repaired the exterior wall of the Guildhall and repainted the doors very carefully considering the historical conservation of the building.

"The council really appreciated the interest and support from the Windsor and Eton Society and the passion they have for our local buildings.

"The Guildhall is a much loved treasure in the Royal Borough and we are incredibly proud to have it as a council building and open to the public as well as for weddings and other occasions."

A spokesman for the Royal Borough  later revealed that  a start date for repairing the windows had been set for March but delayed by the Coronavirus, adding: "We are currently awaiting a new start date from the contractor."