The debate on the same-sex marriage referendum should have a "responsible tone", Minister for Transport Paschal Donohoe has said.

Mr Donohoe said the Government and groups on the Yes side were putting together a “very positive agenda” to demonstrate why they believed the referendum should pass.

“I cannot for the life of me see why looking to make the institutions of marriage available to more people with all of the responsibilities and all of the protections that that affords . . . would deliver a weakening or a diluting of it.”

“I think there has been a really great response to the campaign that is now building at the moment. I think it’s really important that in the coming weeks that everybody does all they can to maintain a responsible tone in relation to this issue.”

‘Concerns and worries’

Mr Donohoe said any “concerns and worries” that people might have would be responded to by the Yes side.

“I’m really confident that we can [address issues] in a positive manner and it will see the passage of this referendum.”

Mr Donohoe said matters contained in the recently-passed Children and Family Relationships Act were "very separate and different" to the referendum.

The Minister was speaking in Dublin following the announcement that the one millionth Leap card had been acquired.