When I was elected as MP for Wycombe in 2001, Cheryl Gillan was one of five constituency neighbours: the others being David Lidington, Dominic Grieve, John Bercow, and two future party leaders: Boris Johnson (across the county border in Oxfordshire) and Theresa May (ditto, Berkshire).

Cheryl had been in business in marketing, and was first elected to the Commons in 1992 – at a time when Conservative women MPs were fewer.

By 2001, she was senior, experienced and, with Lidington, the longest-serving of my four Bucks colleagues.  Cheryl was also able (having served as a junior Minister in the John Major Government at Education) and was a consistent presence on the Opposition front bench during my ten years in the Commons.

My sharpest memories of her are Bucks memories: that’s to say, of her around the table at joint meetings of the County Council Cabinet and those local MPs.

Kindly one-on-one, she was formidable across the table – woe betide the unfortunate person who happened to cross her – and in my view the most imposing character of the five of us, at a time when that smaller number of Tory women MPs had to work even harder for their place in the sun.

She was also what Conservative MPs call “a good colleague”: that’s to say, any disagreement she had with you would be argued out privately, and in public she would “have your back”.

A key to Cheryl was her husband, John “Jack” Leeming, a former senior civil servant, to whom she was devoted, and the attachment was mutual.  It was a warm, close family circle that kept her going during “expenses”, and his death two years ago will have been a terrible blow to her.

At one point, she was ready to stand down in 2019; changed her mind; stood again and won.  Part of the explanation for the back-and-forth may be found in the leadership contest of earlier that year.

Graham Brady’s leadership aspirations effectively excluded him from acting as returning officer for the election.  So Cheryl, by then a Vice-Chairman of the 1922, acted as returing officer with the other Vice-Chairman – Charles Walker or “my beautiful assistant”, as she referred to him while announcing the result [see picture right].

Cheryl may have stood for Parliament again believing it possible that Brady would not contest the chairmanship of the ’22 post-election, leaving the way open for her to do so.

It is not at all surprising that, back in 2010 after her long front bench stretch in Opposition, she survived the cull of Conservative Shadow Cabinet members when the Coalition was formed – moving from shadowing the Welsh Secretary to serving in the post herself.

Other Tory MPs might have been intimidated by Labour’s stranglehood on the politics of the country – her main claim to the office was that she had been born in Cardiff – but Cheryl was a vigorous presence in post, and didn’t want to leave it when dismissed by David Cameron in 2012.

In retrospect, it may have been for the best, since the tensions between serving as a loyal Minister, which she was, and opposing HS2, which she did, were rising.

She was a vociferous, well-informed and constant opponent of the project, and of its consequences for her Chesham and Amersham constituents.  Cheryl leaves a majority of 16,223, and the coming by-election will be a test for Ed Davey’s Liberal Democrats, who will want to mount a challenge, and to the Tories, who will be expected to dismiss it.