She was elected to Parliament in a by-election in May 1984 following the death of Ioan Evans, and became the first woman to sit for a Welsh valleys constituency.

Her election came in the midst of the biggest industrial dispute since 1926, which was the 1984-85 coal miners' strike, in one of the mining constituencies most deeply affected.

Clwyd served as Shadow Minister of Education and Women's Rights from 1987,[1] but was sacked in 1988 for rebelling against the party whip on further spending on nuclear weapons.

[5][6] Clwyd was the Opposition Spokesperson for Employment from 1993 to 1994,[1] and for Foreign Affairs from 1994 to 1995,[1] when she was again sacked, along with Jim Cousins, for observing the Turkish invasion of Iraqi Kirkuk without permission.

[8] However, she subsequently changed her mind but was told that she would need to go through a reselection process as the procedure to find her successor had already been put in train by the Labour Party.

[9] On 13 December 2014, she was reselected from an all-women shortlist as the Labour Party candidate in Cynon Valley for the 2015 General Election.

Whilst opposition spokesperson for Foreign Affairs, she was sacked along with Jim Cousins for observing the Turkish Army's invasion of Iraqi Kirkuk without permission.

On 12 March 2003, James Mahon made first mention of the claims that some Iraqis were killed in plastic shredders or woodchippers,[14][15] when he addressed the House of Commons after returning from research in northern Iraq.

[16] Later she would add that it was believed to be housed in Abu Ghraib prison, and spoke with an unidentified person who claimed the American-sourced shredders were dismantled "just before the military got there".

[17] As the first journalist to state the unsubstantiated claim, the rolling effect of the gruesome verbal picture garnered wider media and international political support, including from Australian Prime Minister John Howard, for an invasion of Iraq.

The Sun's political editor Trevor Kavanagh wrote in February 2004 that as a result of Clwyd's article "Public opinion swung behind Tony Blair, as voters learned how Saddam fed dissidents feet first into industrial shredders."

In December 2012 Clwyd publicly criticised the standard of nursing care that her husband Owen Roberts had received at the University Hospital of Wales when he was dying there in October 2012.

She held an Honorary Doctorate of Laws from Trinity College, Carmarthen for her contribution to politics and as a human rights campaigner.