Strangford ferry service experienced dozens of breakdowns in 2016
The Strangford ferry service in Northern Ireland has broken down at least 35 times this year, Stormont figures revealed.
A near-£6 million new vessel is still not in service as problems with the ramps mean cars would be unable to drive off it at high tide.
Hundreds of journeys are made using the 10-minute link between Portaferry and Strangford every day and there is no plan B if the only serviceable boat malfunctions, a local representative said.
Alliance Party Assembly Member for Strangford Kellie Armstrong added: "I hope it keeps working. If it does not, the minister (Chris Hazzard) is in trouble."
Official figures obtained by the AM revealed dozens of stoppages on the lifeline route used by school children and hospital patients.
Ms Armstrong said there were 35 breakdowns this year to November, 43 last year, 51 in 2014 and 59 in 2013.
She added: "The boat is not getting a break until 1030 at night. The Portaferry II boat is back and forward and back and forward and the plan B was supposed to be the new boat.
"There is no plan B."
Stormont Executive paid £5.7 million for the bespoke ferry built by Birkenhead-based Cammell Laird.
The firm describes itself as one of the most famous names in British industry and dates back to 1826.
A spokesperson for the shipyard told the BBC: "All handover requests were made. We delivered what we were asked to deliver. The ramp meets the specifications we were given."
The new vessel, called the MV Strangford 2, was originally scheduled to begin operating last summer but will remain docked until the repair work is carried out.
It can take around an hour and a half to travel from Strangford to Portaferry by road via Newtownards. The ferry crosses the mouth of Strangford Lough to the tip of the Ards Penninsula in minutes.
Allison Murphy, a director of the Portaferry and Strangford Trust community organisation, expressed concern.
She said school children from Portaferry and those attending medical appointments relied on the crossing every day to travel to Downpatrick.
"It is vital that they sort this out very quickly. They have known about this for at least three months.
"If the current boat breaks down we have nothing to fall back on."
Stormont's Infrastructure Department said a backup vessel was available while work to modify the ramps was under way.
A statement said: "Discussions are ongoing with the shipbuilder to resolve this issue under the terms of the contract."
It said health and safety was the priority and the MV Strangford II will enter service as soon as a passenger certificate has been issued by the Maritime and Coastguard Agency, expected early in the new year.
"Until then, the current ferry remains fully operational, continuing to service the local community, sailing every 15 minutes during timetabled hours.
"The minister wants to ensure the new ferry comes into operation as soon as possible and will continue to keep the situation under review."