A member of the Labour Party, he was best known for formulating what came to be known as the "West Lothian question", on whether non-English MPs should be able to vote upon English-only matters after political devolution.

[7] He then trained as a teacher at Moray House College in Edinburgh and taught at Bo'ness Academy for three years,[4] and was Director of Studies on the ship school Dunera from 1961 to 1962.

This provided "a conduit for researchers to speak to Parliament and vice versa", covering many subjects of public concern including industrial diseases, data protection, chemical weapons and the environment.

[12] After being unsuccessful as a parliamentary candidate for Roxburgh, Selkirk and Peebles in 1959, he became a Member of Parliament in June 1962, when he defeated William Wolfe of the Scottish National Party in a hard-fought by-election for West Lothian.

Allan Stewart, a former Scottish Office minister and Conservative MP for Eastwood, also said that Coleman should be granted immunity so he could testify in Scotland.

[25] In February 2003, he became the first Father of the House to be ordered to leave the chamber, after asking questions about the government's "dossier" on weapons in Iraq.

[26] Following his outspoken opposition to the 2003 invasion of Iraq and criticism of the Government, Downing Street suggested that he might face withdrawal of the Labour whip.

[27] In May, the American magazine Vanity Fair reported Dalyell indirectly as having said that Prime Minister Tony Blair was unduly influenced by a "cabal of Jewish advisers".

He stated that "since Mr Blair is going ahead with his support for a US attack without unambiguous UN authorisation, he should be branded as a war criminal and sent to The Hague".

It was announced on 13 January 2004 that Dalyell would not seek re-election as an MP at the next general election,[5] and he left the House of Commons in April 2005 after 43 years as a Member of Parliament.

In 2009, The Daily Telegraph reported that Dalyell had submitted an expenses claim for £18,000 for three bookcases just two months before his retirement from the House of Commons.

The dedication is "To the men and women of West Lothian – Labour, SNP, Conservative, Liberal, Communist – who, whatever their political opinions, were kind to me in all sorts of ways over 43 years as their representative in the House of Commons.