While officially tendering a resignation letter to spare the government more embarrassing publicity, Mr Stewart's future was hanging in the balance following his confrontation with demonstrators against the M77.
His son, Jack, and a friend, both 16, have also been reported by the police to the Procurator Fiscal for allegedly carrying a loaded airgun on a visit to the protesters' camp at Pollok Castle Woods, south of Glasgow.
The conventional exchange of letters with the Prime Minister came after Ian Lang, Secretary of State for Scotland, abruptly cancelled a party engagement in Wales.
George Kynoch, who entered Parliament for the first time in 1992 by winning Kincardine & Deeside against the odds, becomes the new Scottish Office Parliamentary Under-Secretary of State.
Mr Kynoch, 48, formerly parliamentary private secretary to Gillian Shephard, Secretary of State for Education, and on the centre-right of the party, is regarded by ministerial colleagues as competent and ambitious but lacking colour.
The departure of Mr Stewart, a convivial and libertarian right-winger, underlines the lack of ministerial material among the handful of Tory MPs north of the border. It was met with jubilation by the motorway protesters and with dismay by his Eastwood constituency, one of Scotland's few safe Tory seats.
Mr Stewart has admitted to the police that he picked up the pickaxe but says he acted in self-defence. Lindsay Keenan, 30, claimed that Mr Stewart jostled him and brandished the axe after using threatening language, when he and a group of about seven others turned up at the campsite and began tearing down protesters' banners. Mr Stewart attacked "wild and innaccurate" allegations in a statement but told Mr Major in his resignation letter he did not wish "in any way to be an embarrassment to a GovernmentI have been proud to serve."
In his reply, Mr Major praised Mr Stewart's skilful stewardship of the Local Government (Scotland) Bill, a Tory gerrymandering measure, through the House of Commons. It was the highpoint of his ministerial career.
The Government becomes a little greyer as he joins the parade of ministers and ministerial aides who have fallen victim to controversy since the 1992 election. While Mr Stewart was almost as popular with opposition MPs as he was with his own side, Labourwas quick to seize on the inexperience of Mr Kynoch as a reminder of the Tories' weakness in Scotland.
After taking account of MPs who are not regarded as suitable material for promotion, the Prime Minister was left with an effective choice between only two possible candidates: Mr Kynoch and the right-wing Raymond Robertson, the MP for Aberdeen South.Reuse content