A former UK transport minister has voiced his frustrations about the train service between Belfast and Dublin.
In a tweet, Labour peer Lord Adonis renamed the Enterprise service, the 'infrequent snail' following his journey between the two cities.
He said connectivity "which is this bad can only do economic harm" and "it needs to be sorted out".
Translink said a cross-border strategy had been in place since June which aims to greatly improve the service.
Antiquated diesel loco & carriages for 1120 Dublin to Belfast. The train is called ‘ENTERPRISE’ but it should be called ‘INFREQUENT SNAIL’ - train once every 2 hours, taking 2 hours for a distance of under 100 miles linking 2 greatest cities of Ireland! pic.twitter.com/kbFUCVerGq— Andrew Adonis (@Andrew_Adonis) August 27, 2018
Speaking on BBC Radio Ulster's Good Morning Ulster programme, Lord Adonis said: "I turned up at Connolly Station in Dublin at 09:30 BST, expecting there to be a train every half hour to an hour. After all, these are the two great cities of Ireland.
"In England, there is a train between London and Birmingham every 20 minutes. I simply couldn't believe it.
"It's 100 miles distance and the trains take two hours and 20 minutes and they get slower on the approach to Belfast from Newry."
Lord Adonis accepted that the Enterprise service was cheaper than many similar train journeys in England.
"Having a low fare and a terrible service is not a great equilibrium," he said.
"You want a good service with good value fares.
"I was shocked at how bad the service was."
Translink said it has already drawn up an "ambitious" development plan with Iarnród Éireann.
"The strategy sets out a road map of how both companies jointly plan to further enhance the service on this important north/south rail corridor," said a Translink spokesperson.
"It envisages the introduction of new fleet to allow for an hourly frequency between the two cities and the ambition to reduce the average journey time to less than two hours within five years.
"The strategy is dependent on additional investment in infrastructure and line improvements."