The Conservative leadership election erupted into a highly visible and damaging row between party grandees yesterday.

In response to Margaret Thatcher's announcement of support for Iain Duncan Smith, former prime minister John Major triggered a day of bitter blood-letting, or an "uncivil war" as the Mirror describes it, after launching a vitriolic attack on the Tory icon's legacy and strongly endorsed Kenneth Clarke's candidacy.

Speaking on Radio 4's Today programme Major accused Thatcher of inciting Tory MP's to vote against the government on Maastricht, and said he thought it "unprecedented to have a former prime minister to be actively encouraging new young Conservative members of Parliament to vote against an existing Conservative government".

In interviews later in the day he repeated claims that she left a legacy of high inflation, rising interest rates and unemployment, reiterating his support for the Clarke candidacy and mounting further attacks on Duncan Smith's past as a Maastricht rebel. Major also made categorical denials that Duncan Smith had ever been offered a front bench role under his administration.

Major was accused by Lord Tebbit last night of being a "bitter man" and alleged that Clarke had approached him in 1990 to unseat Thatcher months before her downfall.