Mr Morris's decisive 3-2 victory over Jack Dromey means that the left- led Transport and General Workers' Union will continue to be an occasional, and sometimes unpredictable, thorn in the side of the leader.
Mr Blair has provisionally accepted an invitation to address the union's conference in three weeks' time when he will have to choose between laying it on the line to the union's activists or mending political bridges.
Mr Dromey, husband of Labour's employment spokeswoman Harriet Harman, abandoned an attempt to challenge the conduct of the ballot. An alleged misuse of union funds could not have produced such a decisive majority, he decided.
In a relatively high turnout for a postal ballot, Mr Morris, 56, arguably Britain's most prominent black man, received 158,909 votes, Mr Dromey 100,056 and Norman Davidson, a Kent agricultural worker, 16,833 votes. Defeat for Mr Dromey, in one of the most acrimonious union elections in recent years, means the Labour leader has been unable to stamp his authority on the union movement in the wake of his Clause IV triumph in the party.
Asked how Mr Blair might take his victory, the newly re-elected general secretary said he did not know how the Labour leader, a T&G member, had voted, but like all other members, Mr Blair was, "highly respected, valued and much loved". Mr Morris said he received a clear mandate to continue his policies of creating a "strong, independent industrial organisation" - a clear reference to Mr Dromey's closeness to the Labour leadership.
He underlined his independence by declaring his commitment to the establishment of a national minimum wage of pounds 4, despite Labour's retreat from setting a figure in advance of the general election.
However, Mr Morris will face a series of searching questions at the union's biennial conference over his claim that he has set the T&G on a sound financial footing. There will also be another critical test of his members' opinion in the autumn when elections are held for the 32- strong general executive, a body from which the leader of the union derives his power.
Despite the bitter nature of the election - Mr Dromey accused him of undermining the party's chances of winning the next election - both men agreed yesterday that the status quo ante would be observed. Mr Morris said there would be no recriminations and Mr Dromey said he would not tolerate "oppositionism" to the general secretary within the union.
Mr Dromey, 46-year-old head of the T&G's public services division, is still regarded as a man with a considerable political future in the labour movement. However he registered his determination to stay at his post. "On Monday I will be back behind my desk ... This is not just a job to me, it is a vocation."Reuse content