THE front-runner to be Labour's candidate in the seat held by disgraced MP Eric Joyce is facing questions over her judgment after she said she would throw a party when Margaret Thatcher dies.

A photo of the 87-year-old former Conservative Prime Minister was posted on left-winger Karie Murphy's public Facebook page in January. It was emblazoned with the words: "One Hellbound Bitch!"

Next to the picture, Ms Murphy, tipped to secure Labour's Westminster candidacy in Falkirk with the backing of the Unite union, wrote: "Having a party when she dies."

After The Herald made inquiries about the entry, the Facebook account was deactivated.

Scottish Tory chief whip John Lamont said: "This is another disgraceful episode, and the leadership in the Labour party must distance themselves from this."

The Falkirk seat is held by Eric Joyce, who quit Labour last year after assaulting four people in a Commons bar. Joyce was arrested again on Thursday after a late-night incident at Westminster.

His looming exit at the General Election means there is now fierce competition to become Labour's candidate in a seat Joyce won in 2010 by 7843 votes.

The main contenders are Murphy, ex-Falkirk Council leader Linda Gow, and Gregor Poynton, UK political director of online media strategists Blue State Digital.

Murphy's lawyers said she "deactivated" her account on Friday but added she "lacks a fondness for any Conservative leader".

There was no comment from Scottish Labour.