At the 1945 general election, Scott-Elliot was elected as Labour Party Member of Parliament for Accrington. His background made him an unlikely recruit for the Labour Party, although he was perfectly sincere in his beliefs that socialist planning was best for business. His connection with the cotton trade helped him make friends among the weavers in the constituency.
Scott-Elliot disagreed with the government's policy of nationalising the steel industry, although not to nationalisation in general, and he did not vote against the whip. In October 1948 he wrote a letter to The Times which accepted the call by dissident Labour MP Ivor Thomas for a political truce and a government of national unity. When Thomas left the Labour Party over opposition to steel nationalisation, the Accrington Trades and Labour Party repudiated the letter, and Scott-Elliot announced that he would not fight the next election.
Post-Parliamentary career
Going back to his estate and business, Scott-Elliot retired in the late 1960s and spent most of his time collecting antiques. His first marriage to Maria von Groeller had been annulled in 1948 and he had remarried that year to Dorothy Nunn, who was much younger than him. He had a London flat at Richmond Court on Sloane Street. In 1977, Scott-Elliot engaged a new butler called Archibald Hall. Unknown to Scott-Elliot, Hall was a thief and a murderer who was interested only in stealing what he could.
Murder
When Dorothy Scott-Elliot interrupted Hall and his accomplice discussing their burglary plans, they suffocated her. When her husband arrived back, he was drugged and the two were driven up to the Scottish highlands. Mrs Scott-Elliot was buried in Perthshire, while Walter Scott-Elliot was driven up to Guisachen, near Inverness, where he was throttled with a scarf, beaten over the head with a spade, and then buried in the forest. Scott-Elliot's status as a former Member of Parliament added some interest to the case of Archibald Hall. Hall was nicknamed "the Monster Butler" by some newspapers. As Scott-Elliot had been murdered in Scotland while Hall's other four murders were committed in England, Hall and accomplice Michael Kitto had to be tried separately in Edinburgh for the murder of Scott-Elliot in May 1978. They were convicted and Hall was given a 15-year tariff which he had to serve before being considered for release. At his subsequent triple-murder trial in London, he was also convicted and given a whole life tariff.