" those scemes virtually rebuilt Britain after the war."

I think you will find the Irish made a massive contribution to rebuilding Britain after the war. Macalpine's Fusiliers may just be a song but it encapsulated an underlying reality.
" A wave of emigration to England took place between the 1930s, and 1960s by Irish escaping poor economic conditions following the establishment of the Irish Free State. This was furthered by the severe labour shortage in Britain during the mid-20th century, which depended largely on Irish immigrants to work in the areas of construction and domestic labour. The extent of the Irish contribution to Britain's construction industry in the 20th century may be gauged from Sir William MacAlpine's 1998 assertion that the contribution of the Irish to the success of his industry had been 'immeasurable'."
"he late 1940s and the 1950s constituted a remarkable era of mass emigration. Over 500,000 people left independent Ireland between 1945 and 1960 and it is estimated 75% came to the UK."