The opponents of a measure which would introduce a constitutional ban on marriages for gay couples in Minnesota have edged slightly ahead, according to a recent poll.

The Public Policy Polling survey released yesterday showed a plurality of 49 percent opposed the amendment, with 43 percent in favour.

Although equal marriage supporters are currently outnumbering opponents in a reversal of the positions in the last poll, where 43 approved of equality in marriage for gay and straight couples and 47 opposed it, some have said it is not statistically significant.

Bill Morris, president of Decision Resources told TwinCities.com: “The difference between support and opposition has never been more than 6 (percentage) points. To see today that supporters of same-sex marriage are now ahead really wasn’t a surprise, it was just confirming the fact that it’s a tight race and we have had some really impactful changes going on in the electorate.”

A year ago, another poll by the same agency found 46 percent supported marriage equality while 45 opposed it.

Support has come from a number of sources. Minnesota’s Conference of the United Methodist Church recently voted to oppose the measure, which would ban marriages between gay people, 400-169.

Retail giant Target, based in Minnesota, is selling a gay pride t-shirt on its website and is donating all proceeds from the sales to the Family Equality Council, which campaigns for a marriage equality in the state.

President Obama’s campaign group in Minnesota issued statement in April saying they would oppose the state’s proposed constitutional amendment.

Kristen Sosanie, spokeswoman for Obama’s Minnesota campaign, said in a statement: “While the President does not weigh in on every single ballot measure in every state, the record is clear that the President has long opposed divisive and discriminatory efforts to deny rights and benefits to same sex couples.

She added: “That’s what the Minnesota ballot initiative would do — it would single out and discriminate against committed gay and lesbian couples — and that’s why the President does not support it.”

A poll in May 2011 found that 72 percent of Minnesota voters supported some form of legal recognition for same-sex couples.