LABOUR lost all three of the late George Wenham's council seats in Hatfield in a triple by-election held last Thursday, June 19.
Tories took the county council division of Hatfield South and the district council ward of Hatfield North with comfortable majorities, and one of Labour's three town council seats in Hatfield Central fell to the Liberal Democrats.
Ms Hazel Laming, who works for the University of Hertfordshire, is the first Lib Dem in history to win an election in Welwyn Hatfield - it was the now-defunct Alliance which held two district council seats more than 15 years ago.
She said: "This is a breakthrough for Liberal Democrats in Welwyn Hatfield, upon which we hope to build in the future."
All three Hatfield Central town council seats were up for grabs, but Labour's Margaret White and Sheila Jones held on to the other two.
The Hatfield North result sees the Tory majority on Welwyn Hatfield Council rise to eight with Councillor Howard Morgan's victory by 141 votes in a 25 per cent turnout.
And Mr Morgan's party colleague Stuart Pile, who sits on Welwyn Hatfield Council's cabinet, will add Hertfordshire County Council to his list of responsibilities following his seizure of Hatfield South by 313 votes.
Turnout in Hatfield South and Hatfield Central was 27 per cent and 19 per cent respectively.
The by-elections were caused by the death of veteran councillor George Wenham on April 23.