The Derby North MP was suspended after he claimed Labour had been “too apologetic” in response to criticism of its handling of anti-Semitism allegations.
Labour is understood to be confident its rules were followed and that there will be no successful grounds for a challenge.
The longer good Labour people stand by a party riddled with anti-Semitism, the more their reputation corrodes. This is the moment when their personal legacy and integrity is at stake, writes Chris Leslie
The Jewish Labour Movement says decision to end suspension of MP "stinks".
Labour leader also could not see a problem with Ken Livingstone 'Hitler' interview, ex-staffer claims.
Call by Hope Not Hate came as the MP was at centre of a fresh anti-Semitism storm.
One fellow MP said he will “get a taste of his own medicine”.
The party is 'looking into' Chris Williamson's comments.
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'It’s just not true,' Labour leader told by backbencher.