Campaigning: Should politicians talk on abortion?
This contrasts with the US, where seven in 10 of voters said that a candidate's handling of the issue would influence how they would vote.
Only 43% of those polled in the UK felt strongly about abortion as a political issue that might change the way they voted.
The results have been used by pro-choice groups in the UK to say that MPs should be more open to debating the issue.
Ian Jones, BPAS chief executive, said: "The results of the MORI poll are a useful insight into voters' views.
"It shows that for half of UK voters, a political candidate's position on abortion is not an important issue in deciding whether or not to vote for that candidate.
"It's about time we recognised that abortion is an essential reproductive healthcare need that people should not be afraid to talk about."
However, the pro-life charity Life said the poll was still clear evidence that many voters were influenced by a candidate's views on abortion.
A spokesman said: "35 years after abortion was legalised we are pleased to see that it still ranks as an important factor for many people when choosing which political candidate to support.
"Whether you believe that you are destroying a human life, or acting in women's best interests, it is too important a subject to ignore.
"Life welcomes all honest debate surrounding abortion.'
South bias
The results of the poll suggested that both single people, and those who live in the south of England are more likely to be influenced by a candidate's opinions about abortion.
Prominent politicians are also keen to see abortion more publicly debated.
Dr Jenny Tonge, Liberal Democrat MP for Richmond Park in London, said: "It is very important for MPs to know that for half the public, a political candidate's position on abortion is not important, and by supporting a woman's right to choose they are speaking for the majority."