Original sentence: Although the Conservative Party was in government for two-thirds of the twentieth century, it has been in opposition in Parliament since losing the 1997 election to the Labour Party, but the Conservative Party are currently ahead in opinion polls
Edited sentence: Although the Conservative Party was in government for two-thirds of the twentieth century, it has been in opposition in Parliament since losing the 1997 election to the Labour Party, but the Conservative Party are set to return to office in the next General Election, in accordance to current opinion polls