As political upheavals go, the night of Thursday November 26th 1981 was pretty high on the Richter scale.

The safe Conservative seat of Crosby was up for re-election following the death of its long-serving MP Sir Graham Page.

Page was returned with a thumping 19,272 majority in the 1979 General Election – and his Tory successor John Butcher was hoping for more of the same three years later.

But this time round there was a new kid on the block – and a brand new political party too.

Victory! Shirley Williams celebrates at the Blundellsands Hotel, Crosby, November 1981

Victory! Shirley Williams celebrates at the Blundellsands Hotel, Crosby, November 1981

The candidate was former Labour front-bencher Shirley Williams and she was part of an irresistible new force – the Social Democratic Party or SDP.

Formed just seven months earlier in March 1981, the SDP was headed by four major figures from the centre-right of the Labour party.

Alongside Williams were former Chancellor Roy Jenkins, ex-Foreign Secretary David Owen and Liverpool-born former Cabinet member Bill Rodgers.

Owen and Rodgers were still in Parliament, but Williams and Jenkins were looking for a way back. Jenkins tried his luck in the Warrington by-election in July, but narrowly missed out to the Labour candidate.

A massive night for the SDP faithful as they take Crosby from the Tories, November 1981

A massive night for the SDP faithful as they take Crosby from the Tories, November 1981

Now it was Williams’ turn. She was boosted by the Liberal party’s decision not to field a candidate at Crosby, preferring instead to support the SDP. The Liberals had polled 15 per cent of the vote in the 1979 election, so it was a significant advantage.

There were other factors in Williams’ favour too. The SDP were on a surge of popularity as people were beginning to tire of Conservative and Labour party in-fighting.

Prime Minister Margaret Thatcher had ruthlessly rooted out the pro-Heath faction and was pursuing an all-out monetarist agenda.

The economy was under severe pressure. Unemployment at nearly three million was at its highest since the 1930s and inflation was running at more than 10 per cent.

Shirley Williams meets Crosby constituents old and (very) young, November 1981

Shirley Williams meets Crosby constituents old and (very) young, November 1981

There had been public unrest in Toxteth and Bristol as well as Handsworth and Brixton in London.

Labour leader Michael Foot was portrayed as weak and unable to control the militant factions of his own party, let alone run a country.

All eyes were therefore on Crosby when Williams started campaigning in earnest against Tory candidate John Butcher – an accountant who was also a Royal Navy reservist.

The Labour hopeful was John Backhouse, a local teacher and Chair of the Crosby Labour Party. Many had expected the 1979 candidate, Tony Mulhearn, to fight the seat for Labour – especially since he was a leading figure on Liverpool City Council.

The SDP ‘Gang of Four’ - Bill Rodgers, Shirley Williams, Roy Jenkins and David Owen, January 1981

The SDP ‘Gang of Four’ – Bill Rodgers, Shirley Williams, Roy Jenkins and David Owen, January 1981

Among the other candidates were local lecturer Richard Small, standing for the Ecology party, and president of the Cambridge University Raving Loony Society John Desmond Lewis.

Before the by-election, he changed his name by deed poll to Tarquin Fin-tim-lin-bin-whin-bim-lim-bus-stop-F’tang-F’tang-Olé-Biscuitbarrel in homage to the Monty Python election night sketch.

He clearly saw himself as a forerunner of Screaming Lord Sutch’s Monster Raving Loony Party which would be founded in 1983.

While the newly named Mr Biscuitbarrel was pursuing a narrow target audience, Williams was appealing on a wider front. A third of Crosby voters were Roman Catholic with 18 churches in the constituency.

Tory Prime Minister Margaret Thatcher and Willie Whitelaw, October 1980

Tory Prime Minister Margaret Thatcher and Willie Whitelaw, October 1980

Williams was a practising Roman Catholic herself. Her father, political scientist and philosopher George Caitlin, had converted to the faith between the wars. What’s more, he was born in Liverpool.

The conditions were ripe for an upset on results night – and so it proved.

Williams swept away the Tory majority by polling no less than 28,118 votes – a colossal 49.07 per cent of the total turn-out.

Conservative candidate Butcher received 22,829 votes, 5,289 less than the jubilant Williams. The Tory majority of 19,272 from the previous election had been wiped out by the SDP avalanche. The negative swing from 1979 was a staggering 17.1 per cent.

Labour party leader Michael Foot, October 1980

Labour party leader Michael Foot, October 1980

Screaming Lord Sutch, left, founder of the Monster Raving Loony Party, June 1983

Screaming Lord Sutch, left, founder of the Monster Raving Loony Party, June 1983

The Labour vote for Backhouse was 5,450, down nearly 16 per cent on 1979, and Ecology candidate Small received 480 votes, down 1.6 per cent.

Mr Biscuitbarrel was the best of the rest, registering 223 votes.

Cosby returned to Conservative hands when Malcolm Thornton won the seat from Williams in the 1983 General Election.

Williams stood for the SDP once more in Cambridge in the 1987 General Election, but lost to Tory candidate Robert Rhodes James.

Toxteth MP Dick Crawley joins Shirley Williams on the SDP campaign trail, November 1981

Toxteth MP Dick Crawley joins Shirley Williams on the SDP campaign trail, November 1981

*Hundreds of remarkable pictures from around Britain during World War II will feature in Clive Hardy’s latest book The Home Front – 1939 to 1945, available soon from publishers iNostalgia.