Wedding suppliers and hoteliers across Ireland are set to reap a $16m annual bonanza from the pink pound if same-sex marriage is passed in the upcoming referendum.

With successive polls showing overwhelming support for the 'Yes' campaign, major players in the Irish wedding industry are preparing for what they say will be their biggest boost in business in years.

Industry sources have predicted that up to 600 same-sex weddings will take place in Ireland in the first post-referendum year, if voters opt to change the constitution on May 22.

With Irish couples already spending an average of $27,000 on their big day, that means traders in the resurgent wedding industry could conservatively expect to reap an extra $16m a year – but probably far more, as gay couples tend to outspend their heterosexual counterparts.

Marian Purcell, who runs Limerick-based information site Gay Weddings Ireland, said her service has never been more in-demand, with business up by over 50 percent since she started in 2012.

But she believes the rewards for the industry could be even greater if Ireland is marketed abroad as a leading destination for same-sex couples to tie the knot in.

She said: "The potential is massive. There are already lots of weddings booked and ready to go after the referendum. There are many other gay couples making preparations now for summer weddings.

"I've already had inquiries from gay couples in New York about getting married here and if we're seen internationally as a country that's accepting of gay marriage, that could be worth millions more to the economy. There's no doubt that this is going to give a huge boost to the economy and tourism."

Since civil partnership first became publicly available in April 2011, hoteliers and traders in the wedding industry have been increasingly targeting the pink pound.

The demand for celebrants has also exploded in this period as couples, both straight and gay, increasingly look to personalize their ceremonies.

Lorraine Mancey O'Brien, who runs 'Marry Me Ireland,' the country's only professional celebrant organization, said: "There's a huge demand at the moment. We've been doing about 20 weddings a month, but we've seen a big increase since January. Just last week we were involved in eight different weddings in one day.

"The demand is only going to increase if same-sex marriage is introduced and I think there'll be a lot of business from abroad, if this country is marketed as a gay-friendly destination."

She added: "We have 14 celebrants on our books at the moment, but by next year we plan to have 50 in total, based all around the country."