Labour can overcome its deep split over Trident and make a collective decision on whether to back renewal of Britain's nuclear deterrent, shadow defence secretary Emily Thornberry has told ITV News.
Andy Burnham, the shadow home secretary, who is pro-Trident, said it may be "impossible" for the party to reach agreement on the issue.
But Ms Thornberry, who wants to scrap Trident like Labour leader Jeremy Corbyn, said while it was going to be "difficult", she "wouldn't be doing this job if I didn't think it was possible for us to reach a collective decision".
She was heckled at a fiery meeting of Labour MPs on Monday night, with one branding her "waffly and incoherent".
Others also branded her suggestion that underwater drones could soon make Trident obsolete as "silly".
Ms Thornberry, who is leading a review of her party's defence policy, hit back at the criticism, urging her colleagues not to look at the issue of Trident "through the lens of the 1980s".
"We must look at this as brave and bold people who are prepared to ask difficult questions."
Mrs Thornberry previously admitted to ITV News that she did not know why Mr Corbyn gave her the job.