The Liberal Democrats “stand to lose hundreds of thousands of pounds” after cancelling their autumn conference due to the death of the Queen.

Nick da Costa, who chairs the party’s federal conference committee, said the Lib Dems “want and need to show our respect to the Queen and the period of national mourning”.

He added the party considered other options – including delaying it by a few weeks – but decided to cancel the event, noting they will take a “substantial financial hit” and “coping with this will not be easy”.

The conference in Brighton was due to begin on September 17 and run until September 20, with the Queen’s funeral scheduled for September 19.

Mr da Costa, in an email update, said: “The sad news of the last few days has touched our nation deeply. And we now know that the Queen’s funeral will take place on the Monday of our conference.

“After very careful consideration – and taking soundings from as many people as we can – the conference committee and federal board have together regretfully decided to cancel our autumn conference and postpone major debates until spring.”

Mr da Costa said the party considered extending the conference, delaying by a few weeks or moving it online but has opted to cancel it, adding: “Conference is a major part of our budget and we stand to lose hundreds of thousands of pounds through this cancellation in lost income. (Event insurance policies do not cover the death of a monarch.)

“At this point many of our supplier contracts are unavoidable. This means that our party will take a substantial financial hit as a result of cancelling the conference. Our finances are already very stretched and so coping with this will not be easy.”

A Lib Dem spokesperson said: “As we mourn the loss of the Queen, we send our condolences to the King and the royal family.

“Given the date of the funeral and period of national mourning, we have decided to cancel our autumn conference. We look forward to welcoming members to our next conference.”

The Labour Party conference is scheduled to run from September 25-28 in Liverpool, while the Conservatives are due in Birmingham from October 2-5.

The London to Brighton Cycle goes ahead today.