Sinn Féin will move a motion in the Dáil this week calling on the government to honour its commitment to fund 50% of the cost of the A5 upgrade.
More than 50 people have died in incidents on this route since 2006, with ten deaths between October 2021 and October 2022 alone.
Deputy Pearse Doherty is also calling on the government to take all necessary steps to ensure that the Ten-T Road upgrade projects for Donegal, connecting to the A5 and related N2 upgrades receive approval and are delivered as speedily as possible.
Speaking ahead of a Sinn Féin Dáil motion on the issue, he said that the A5 upgrade is critical to prevent further lives from being lost, and to enhance the social and economic wellbeing of the North West region.
The most recent cost estimate of the upgrade is £1.6bn.
Deputy Doherty said: “The A5 upgrade was first announced in 2007 in order to transform a dangerous single-lane road into a much safer dual carriageway but 16 years on we are still waiting.
“We cannot wait any longer. We must act to save lives and protect families from further heartbreak.
“The A5 route is important infrastructure linking north and south – a major route for those living and working in the border counties and right across the North West.
“On Tuesday, Sinn Féin will move a motion in the Dáil calling on the government to honour its commitment to fund 50% of the cost of the A5 upgrade, as committed to as past of the St Andrews agreement so that it is commenced and completed as quickly as possible.
“This would save lives and create jobs as well as enhancing the social and economic wellbeing of the North West region.”
Deputy Doherty added: “There can be no more delays, and no more lives lost. It is time to build the A5 road.”
The issue was raised in the Dáil also in May, following the tragic death of three members of the same family near Aughnacloy.
At the time, Minister for Finance Deputy Michael McGrath said that the Government has committed to provide funding of £75 million towards the cost of the A5 upgrade scheme once the statutory planning process in Northern Ireland has been concluded. The Minister agreed that the project is “well overdue”, adding that the Irish Government “will not be found wanting” in its support of the project.