Happy returns to No 10 for Thatcher's 85th birthday

Lord Heseltine is not on the list. John Major is out of the country, and Nick Clegg has "another engagement". But Lord Howe, whose resignation speech ended Margaret Thatcher's reign in Downing Street, will today be a guest of honour at the former prime minister's 85th birthday party in Downing Street.

About 150 ministers, former ministers, MPs, and peers with careers stretching back over the last 40 years have been invited to the reception at No 10 – the largest gathering of Thatcherite ministers in Downing Street since they themselves sat around the cabinet table more than 20 years ago. The bash was announced by David Cameron to cheers at the Conservative Party conference earlier this month.

Lord Heseltine, who brought Mrs Thatcher’s premiership to an end when he stood against her for the leadership, was left off the guestlist which was co-ordinated between her office and Downing Street.

“I don’t think he’s on the list,” said a spokesman for Baroness Thatcher, adding: “But most of her former cabinet ministers have been invited.”

That includes Lord Howe, Mrs Thatcher’s then deputy, whose famous resignation speech accused her of being like a cricket captain “sending your opening batsmen to the crease, only for them to find that their bats have been broken by the team captain”.

Last night he hinted that they had since patched up their differences. “I went to her 80th birthday party and she came to mine,” he said. “That’s all there is to say really.”

Among those attending will be Leon Brittan, who was forced to resign along side Lord Heseltine in the Westland crisis, Michael Howard, Sir Bernard Ingham – the Alastair Campbell of his day who once described a cabinet minister as “semi-detached” – and Lord Carrington, Baroness Thatcher’s first Foreign Secretary.

Nick Clegg, the current deputy Prime Minister, whose office is a minute’s walk from the reception, will not be there. A spokesman said he had another engagement at the time: “To be honest it’s a Tory affair with quite a limited invite list. It would be slightly odd for someone who had no real connection with her to just bowl up.”

Also missing will be Sir John Major, who succeeded Baroness Thatcher as Prime Minister. A spokeswoman for Sir John said the date clashed with a previous overseas engagement: “Very sadly he has had to decline as it is the one night this month when he is out of the country. I’m sure it will be a lovely party. He will be there in spirit.”

Other notable absentees include Chris Patten, who is in Japan on business, and Lord Tim Bell, her image adviser when she was in Downing Street. “Sadly,” said Lord Bell, “when I got the invitation I already had a prior engagement so had to decline. I’m very disappointed not to be there as this will be the first time that David has invited her back in an official capacity.”

The media will be kept at bay. No photographers or journalists will be allowed inside.

A Conservative spokesman said: “The idea is it will be an informal affair with just a few words from the Prime Minister. Perhaps they’ll sing her happy birthday.”

Baroness Thatcher’s actual birthday is today. She plans to spend it quietly with friends, her spokesman said.