Midlothian in Scotland is a county constituency of the House of Commons of the Parliament of the United Kingdom.
It elects one Member of Parliament (MP) by the first-past-the-post voting system.
In the 1983 reforms the constituency was significantly reduced from over 100,000 voters to 61,143, with large numbers of voters moved to the new seat of Livingston, and smaller numbers to Edinburgh Pentlands, East Lothian and Tweeddale, Ettrick and Lauderdale.
[1] The 1997 reforms moved Penicuik into Tweeddale, Ettrick and Lauderdale, with the rest of the council area remaining in the seat;[2] it returned in 2005, when the constituency was expanded again to cover the entire Midlothian Council area.
[3] Under the 2023 review of Westminster constituencies, which came into effect for the 2024 general election, the boundaries were unchanged.