The Northern Ireland Secretary is preventing many same-sex couples from planning their weddings, one of the first to legally marry said.
Sharni and Robyn Edwards-Peoples criticised Brandon Lewis for the delay in laying regulations at Parliament.
Those who want to convert existing civil partnerships to marriages are still unable to do so.
They called for urgent action on the one-year anniversary of the House of Commons vote to extend same-sex marriage to Northern Ireland, which passed following an amendment from Conor McGinn MP.
Sharni Edwards-Peoples said: “By not laying the necessary regulations at Parliament, the Secretary of State is stopping many couples from being able to plan their own big day.”
Same-sex civil marriage became legal in Northern Ireland on January 13 this year, and the first wedding took place on February 11 when Sharni Edwards and Robyn Peoples married in Carrickfergus.
However, couples who wish to have a religious ceremony as part of their wedding, or who wish to convert their civil partnership to a marriage, are still not able to do so.
Campaigners want Mr Lewis to lay new regulations in Parliament and introduce these changes as a matter of urgency.
Weddings in Northern Ireland can take place indoors from this Friday, the Stormont Executive has agreed, as part of the relaxation of Covid-19 restrictions.
Sharni Edwards-Peoples said: “We loved having our big day back in February surrounded by the people we love.
“It was a dream day for us and we want everyone to have the same chance to enjoy that feeling.”
Robyn Edwards-Peoples said as we emerge from lockdown, and with weddings now permitted, there will be a lot of couples hoping to have long-awaited wedding days.
“But same-sex couples like us, who want to have a religious ceremony or who want to convert their civil partnership, can’t even plan a date for their weddings at the moment.”
A UK Government spokesperson said: “The Government legislated for same-sex civil marriage in Northern Ireland from January 13 2020.
“We intend to lay regulations next week to allow for same-sex religious marriage in Northern Ireland to come into effect from September 1 2020.
“Conversion entitlements regulations will follow as soon as possible before the end of 2020.”