Veteran Labour MP Ivan Lewis has accused a party backbencher of "manipulating" internal party politics.
Mr Lewis, the Shadow Northern Ireland minister and a former vice-chair of Labour Friends of Israel, appeared to claim Tom Watson had tried to influence the selection process for a new Scottish Labour leader.
Mr Watson wrote an article for the Sunday Herald newspaper warning against Scottish campaign favourite Jim Murphy. There has already been criticism of Mr Murphy in Scotland over his support for Israel.
Mr Lewis, who is Jewish and served as Middle East Minister in the last Labour government, posted a tweet, not addressed to Mr Watson, which said it was "essential that Scots decide best person to be leader of Scottish Labour. Others interfering not in the interests of the Labour Party".
