A decision on whether to approve plans for a new Roman Quarter in York was postponed following the announcement of the death of Queen Elizabeth II mid-way through the meeting.
Councillors, members of the public and the developers had spent around two hours discussing the proposal before Buckingham Palace announced her death at 6.30pm on Thursday.
Planning committee chair Cllr Chris Cullwick announced a break in the meeting before it was reconvened and a full adjournment was announced.
He said: “We’ve heard the sad news of the death of Her Majesty Queen Elizabeth and in the light of that sad news from the palace this evening, I have discussed with fellow members and consulted with the vice chair appointed.
“We feel that it is appropriate that we discontinue the meeting at this time to be adjourned.”
Councillors, officers and other participants at the meeting at West Offices then stood for a minute’s silence.
The proposal is to create a new, underground Roman museum – Eboracum – along with an 88-room aparthotel, 153 new apartments and new office space.
It has divided heritage experts but the vast majority of representations to the council about the scheme are supportive.