Charles is believed to have invited Prime Minister Sir Keir Starmer, as well as first ministers from the devolved nations to a dinner on Wednesday.
The joint trip came days before Sir Keir is expected to set out further measures as part of a pledge to build 1.5 million homes ahead of the next election.
Some of the devolved leaders will stay the night at the royal residence before having breakfast there in the morning, GB News reported.
The King took the Prime Minister and his deputy on a visit to a Cornish development he inspired.
The King is to host political leaders at Windsor Castle, according to reports.
