Probably a miniseries, 3 or 4 episodes, about a woman Labour activist and then MP who joins the party as a young radical, and gradually gets more centrist and what would later be called Blairite. I think it was around 1993 or 1994, though it's not unknown for me to be out by a few years! I mentioned it in a conversation at work today, but it didn't ring a bell for anyone else.