TV crews set up outside Kensington Palace last week in anticipation of an announcement that never came, but royal-watchers are not giving up yet

Was it supposed to have happened last Thursday? Maybe it will be this Tuesday? Speculation and rumour about a possible engagement announcement from the US actor Meghan Markle and Prince Harry reached fever pitch at the weekend, although Kensington Palace aides are keeping tight-lipped.

For months it has been clear the fifth in line to the throne has found a serious partner in the star of the TV legal drama Suits, whom he met in summer 2016. But the sense that an engagement announcement is imminent has been stoked by reports that Markle has already packed up her rented Toronto house and is moving into Nottingham Cottage, the prince’s home in the grounds of Kensington Palace. The 36-year-old American divorcee was photographed shopping on Kings Road, Chelsea, last week.

The bookmaker Ladbrokes stopped taking bets on the engagement last week and Sunday saw press reports that Theresa May had “cleared her diary” on Thursday in expectation of an announcement. This was emphatically denied by Downing Street, which pointed out that less than 24 hours after the budget, the prime minister had other priorities, such as spending half a day in Leeds with the chancellor, Philip Hammond, to promote the government’s house-building policies.

Thursday, however, did see a flurry of activity, with TV crews setting up outside the gates of Kensington Palace and a deluge of press inquiries to Prince Harry’s communications team, all wrongly anticipating an announcement.

There is now media speculation, although it is not clear on what it is founded, that it could come as soon as Monday, or possibly Tuesday. The Mail on Sunday summed up the mood among those for whom any development in the Harry and Meghan show means a ratings boost, with its front-page headline: “The Palace is primed, the nation awaits… so do hurry up, Harry!”

The expectation reflects the desire among royal-watchers for a new storyline in the British monarchy, starting perhaps with Markle attending the Windsors’ traditional Christmas Day celebrations at Sandringham.

It was reported last month that the couple went for tea with the Queen at Buckingham Palace, which some observers inferred involved seeking the monarch’s blessing for an engagement.

Kensington Palace declined to engage with questions about a possible announcement on Sunday, and even a usually talkative royal source responded with a dry: “No comment.”