Complex sentence: The Progressive Party was the name of a defunct municipal political organisation that operated in several Scottish cities and towns in the 20th century but based around tacit anti-Labour co-operation between the Unionist Party, Scottish Liberals and Independents.
Split into simpler sentences: The Progressive Party was a municipal political organisation that operated in several Scottish cities and towns in the 20th century. It was based on tacit anti-Labour co-operation between the Unionist Party, Scottish Liberals and Independents.