Former home secretary David Blunkett said that "anti-Semitism" and "theft" within the workplace make him desperate, aggravating some difficult days for the party.
Lord Blunkett, who was a parliamentarian for 28 years before becoming a Labor peer, said that the probability of Jeremy Corbyn winning the majority is "extraordinarily slim".
But he called on the moderates within the party to "stay and fight" to ensure that the "voice of reason" prevailed, following the decision of deputy leader Tom Watson to withdraw.
The comments of the former government minister arrived after two of his former MPs urged voters to support the Tories. Ian Austin and John Woodcock said they would support the conservatives because they didn't believe Corbyn was right to be at no. 10.
And on Friday, Dame Margaret Hodge – one of the most important Jewish figures in the work – refused to support the opposition leader as prime minister.
Writing in the Telegraph, Blunkett said: "The behavior of the left endures within the Labor party – the anti-Semitism, the criminal, irrational opinions on security and international issues and the lack of awareness that you have to embrace great tent of people to win – it certainly makes me despair.
"But it also makes a large-scale Labor majority in these general elections extremely likely. The political landscape at the moment is completely different from what the hard left wants you to believe.
"We are in a situation here in 1983, not in 2017 – with not only Lib Dems and Greens, but the Brexit party, the Tories and the SNP all seriously vying for the traditional Labor votes".
The conservative party led by Margaret Thatcher obtained a considerable majority in the 1983 elections, after the votes for the opposition were divided between the work and the liberal alliance / SDP.