New York City mayoral candidate Bill Thompson will announce this morning that he will concede the Democratic primary to Bill de Blasio, according to news reports. Thompson had initially vowed to stay in the race until every vote was counted after the initial tally in last Tuesday’s election showed de Blasio barely clearing the 40 percent threshold needed to avoid a run-off. Sources told the New York Daily News that Thompson changed his mind after the City Board of Elections began rechecking the vote count over the weekend and the numbers didn’t move. Thompson plans to ”make remarks on his 2013 Mayoral race” at an 11 a.m. press conference on the steps of City Hall.

UPDATE: Thompson threw his support behind de Blasio at the press conference, saying, “Bill de Blasio and I want to move our city forward in the same direction. This is bigger than either one of us.” He was joined by Governor Andrew Cuomo, who had declined to endorse either of the candidates during the primary but is now backing de Blasio against Republican nominee Joe Lhota, despite Lhota having served in Cuomo’s cabinet as chairman of the Metropolitan Transit Authority.

“There is nothing more beautiful than Democratic unity, and thank you for it,” said de Blasio.