Britain is demanding that Guyana recall its parliament and allow suspended MPs to approve key laws.
Andrew Ayre, Britain's high commissioner to the South American country, said President Donald Ramotar should act swiftly to resume sittings of the 65-member National Assembly. He said the move was necessary to preserve democracy.
Mr Ramotar suspended the assembly on November 10 for a maximum of six months to halt a no-confidence debate.
The move would allow his administration to negotiate with the opposition-controlled parliament on a legislative agenda without calling early elections.
An opposition party filed the no-confidence vote in September after accusing the government of being "recalcitrant and renegade".