The phrase "vote loser" refers to a person, policy, or action that is likely to cause a political candidate or party to lose support or votes from the public. Full definition
All of the above have consistently been sold as vote losers, if not electoral suicide. (theconversation.com)
The first group still loves Mr Corbyn, the second group still rejects him and much of the vital third group see him as a principled but wrong - headed vote loser. (yougov.co.uk)
I think the days are over, when a governing party puts in a manifesto a known potential net vote loser are over (e.g dementia tax). (ukpollingreport.co.uk)