Shadow home secretary Andy Burnham is considering running for the mayor of Greater Manchester.
His spokesman said he has not yet made a final decision on whether to stand or not.
The health secretary has said he hopes the British Medical Association will "take up the offer to talk constructively" over the junior doctors' contracts row.
Jeremy Hunt's comments come after health ministers offered to "pause" imposition of the contract and to reopen talks on all "outstanding issues" - including Saturday pay - if the BMA agreed to halt discussions of possible future strike action.
Mr Hunt said: "The junior doctors committee is meeting on Saturday and we are seeking assurances following that meeting by close of play that they will negotiate constructively on the outstanding areas of disagreement."
At least 28 are dead after an airstrike hit a refugee camp in Syria, according to the Syrian Observatory for Human Rights.
The number of dead at the camp near the Turkish border included women and children and is expected to rise because of the number of seriously injured people, the Observatory said.
The camp, near the rebel-held town of Sarmada in Idlib Province, was sheltering Syrians displaced by the civil war.
Fighting continues to rage in Sarmada, which is just 20 miles west of the city of Aleppo, despite a temporary deal to cease hostilities in the city being agreed yesterday.