The Queen was reportedly “disappointed” by the Prime Minister’s refusal to discuss plans for Brexit during her first stay at Balmoral.

Theresa May stuck to her “Brexit means Brexit” line during the visit to Scotland in September, rather than giving the royals an insider briefing on how she intended to negotiate Britain’s way out of the EU, a source close to the monarch told The Times.

The Tory leader’s secrecy allegedly upset the Queen, who is said to consider the Prime Minister’s autumnal visit to Balmoral a chance to develop a closer and less formal relationship with whoever is running the country.

Ms May’s visit was somewhat ill-timed, however, coming just two months after she took over from David Cameron, when the Government was still recovering from the upheaval wrought by the referendum.

The Prime Minister, who quietly backed the Remain side but largely abstained from campaigning, is unlikely to have formulated clear plans for the process at that stage. But even so, the Queen was reportedly hoping for more insight.

The women had met for weekly audiences at Buckingham Palace but according to biographer Robert Lacey, the Queen considers a visit to Balmoral as an opportunity to extend the “audience” process between Prime Minister and monarch, and to further develop trust.

But Ms May, who has said she does not want to give a “running commentary” on Brexit, is said to have declined the opportunity to confide in the royals.

The Times emphasised there was nothing to suggest the Queen and Ms May did not get along on a personal level or that they had political disagreements, but their relationship did not get off to a great start because the Queen and the Duke had been looking forward to hearing more about Ms May’s thoughts on Brexit and were left disappointed.

The weekend is a non-negotiable fixture of the Prime Minister’s political diary – even Margaret Thatcher, who initially described the trips as akin to “purgatory”, could not get out of it.

According to a source who was close to David Cameron when he was at No 10, the Queen had a good rapport with her 12th prime minister, who enjoyed the visits and would have confided his innermost thoughts knowing there was no danger that they would have leaked. “He would have quite happily taken the Queen into his confidence," the source told The Times. “I know that he would have been quite open.”

Tony Blair, meanwhile, was reportedly so comfortable in the castle that his fourth son Leo was conceived there, when his wife Cherie forgot to pack her ordinary contraception.

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Previous accounts of Ms May’s visit were more positive. One newspaper suggested that the two women “got on famously”, adding: “There hasn’t been a PM since Harold Wilson who entered so gamely into the outdoor pursuits, parlour games and well-regulated rituals.”

Both Buckingham Palace and Downing Street refused to comment on the claims about Ms May.