I always figured Harriet Jones was Labour, especially given that RTD based her in part on Harriet Harmon (not too well based on her since I like Harriet Jones however

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Honestly, I always figured that Harriet Jones was Lib Dem. She said that she was "hardly one of the 'Babes' " in "Aliens of London" in explaining why the PM hadn't been willing to meet with her (before the Slitheen killed him), implying that she wasn't Labour, and, well, I just can't imagine RTD writing an admirable Tory MP.
I figured Green was Labour as well actually. Although somewhat posh it's worth noting that Blair had more of a privillidged upbringing than either Major or Thatcher, and there's definitely something of Labour spin about Green's government...
I'm curious what the "Labour spin" about Green's government was. They seemed to go out of their way to make Green as deliberately non-partisan in his evil as possible.