LISBON (Reuters) - The number of Portuguese expected to vote in next month's referendum on abortion is rising, a poll showed on Friday, raising the likelihood the ban will be lifted in the Catholic country.

On February 11 Portugal, one of a few countries in Europe that still bans abortions, will hold a vote to decriminalise abortion in the first 10 weeks of pregnancy.

The majority of Portuguese are in favour of lifting the ban, but turnout must be above 50 percent for the vote to be valid.

A poll last week suggested the pro-abortion lobby, which includes the ruling Socialists, could be thwarted because less than 50 percent of the electorate would vote, invalidating the result.

The poll carried out by Publico daily showed that 62 percent were expected to vote and 60 percent of the electorate favoured lifting the ban. Just 29 percent of potential voters are against it.

Voter turnout is expected to be stronger among those who wish to approve abortion. According to the poll, 70 percent of the "yes" camp intend to show up against 30 percent of the "no" camp.

A 1998 referendum narrowly defeated decriminalising abortion but voter abstention was 68.5 percent, invalidating the result.