The MP for West Tyrone, Barry McElduff, has announced his resignation in the wake of the controversy over the 'Kingsmill' video controversy.
He said he took the decision 'because of the Twitter video which caused so much controversy last week'.
Mr McElduff said: "It is with great sadness that, after more than 30 years as an active Sinn Fein member and public representative, I am tendering my resignation for West Tyrone."
He also offered his 'profound apology' to the families of those murdered in the Kingsmill massacre.
"The deep and unnecessary hurt this video caused the families of Kingsmill is my greatest regret."
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