MANCHESTER, England, Sept 24 (Reuters) - Britain's parliament could be recalled as early as Friday to vote on a proposal by Prime Minister David Cameron for the country to join U.S.-led air strikes against Islamic State in Iraq, a source familiar with the matter said on Wednesday. The decision to strike in Iraq would be at Baghdad's request. Cameron is due to meet Iraqi Prime Minister Haider al-Abadi in New York on the sidelines of the U.N. General Assembly later on Wednesday. ...