LONDON - Britain's government published internal legal advice it had been given on Thursday which it said showed it was legally entitled to take military action against Syria even if the United Nations Security Council blocked such action.It also published intelligence material on last week's chemical weapons attack in Syria, saying there was no doubt that such an attack had taken place, that it was "highly likely" that the Syrian government had been behind it, and that there was "some" intelligence to suggest that was the case.