Bernard Harkin, who lost to the SNP in Midlothian North and Musselburgh, said Labour had to offer a clear message to voters.
He said: “There is no point in us reversing or changing our position on major issues weeks before an election, the public will not take us seriously.”
Writing on the Labour Hame website, he added: “We should be a party that is willing to lead public opinion, even on issues that may not be that popular.
“Of course, we need to appeal to voters. However, it is rare for voters to agree 100 per cent with the views of the party they support. But I think they will respect a party and still vote for it if that party stays true to its values.”