Angela Eagle has refused to answer whether "it's time to put up or shut up" in launching a Labour leadership bid, but has once again insisted Jeremy Corbyn "needs to go".
When quizzed on Thursday morning on whether she will finally table a bid, the former shadow business secretary said: "The country doesn't have an effective opposition at the moment."
She added: "Jeremy Corbyn needs to go."
Eagle is widely-considered to be a front runner to challenge Corbyn if he continues to resist calls to stand down.
On Wednesday, she held a meeting with Deputy Labour leader Tom Watson and ex-shadow work and pensions secretary Owen Smith - who is also considering a challenge - to break the impasse.
Labour rebels fear Corbyn would easily win another leadership election due to his support from party members.