NORTHERN Ireland is "on the verge of an electricity supply crisis" according to the man responsible for the north's grid.
Robin McCormick, general manger of the System Operator for Northern Ireland (Soni) wants to see plans for a north-south interconnector moved forward.
The £200 million project would connect the electricity grids across Ireland but proposals - which have been on the table since 2009 - have got caught up in controversy.
Today, Mr McCormick will warn Westminster politicians the situation in his view is "now critical".
The government's Northern Ireland affairs committee is staging an inquiry into the north's electricity sector.
And this morning it will take evidence from Soni (the applicants for the interconnector) and Northern Ireland's Utility Regulator.
Speaking ahead of his appearance, Mr McCormick said he wouldn't "sugar coat the severity of the situation".
Proposals for the interconnector have been delayed as objectors claimed it will be a blot on the landscape with some saying it could pose a risk to health.
If given the go-ahead, will see a series of overhead cables running from just north of Moy in Co Tyrone to Kingscourt in Co Cavan.
A public inquiry by the Planning Appeals Commission (PAC) was first announced as far back as 2010 but it was adjourned in 2012 shortly after opening due to the plans and environmental statement not being properly advertised by previous applicant Northern Ireland Electricity (NIE).
It only got under way again in June this year when preliminary issues were discussed.
Mr McCormick will tell MPs the north is "facing an electricity supply crisis as old conventional fossil fuel generators retire".
“Our modelling of electricity demand and available generation capacity tells us that over the next five years we will be at a point where we are in electricity generation deficit," he added
"What that means is that as the system operator, I cannot be confident that we would be able to ‘keep the lights on’.
“It has been possible to temporarily defer the problem with a short term solution provided by a local power station. However this safety net is costing Northern Ireland consumers an additional £8 million per year and is not sustainable.
“The problem can be addressed by delivering the north-south interconnector, which is now absolutely critical and cannot suffer any further delay.
"With the interconnector in place, customers in Northern Ireland will benefit from having access to the most economic generation capacity available on the island and we can then be confident that we can ‘keep the lights on’.”
But Mr McCormick said he remained hopeful a full planning hearing inthe project could start "by the end of the year".
"It is critical and essential to the NI Economy; to businesses large and small and to domestic users. It is fundamental that Westminster appreciates the urgency and does all it can to support the project.”
The inquiry will also hear from the Utility Regulator's wholesale director Jo Aston and its chief executive Jenny Pyper.
Ms Pyper has previously spoken out against critics of the interconnector including objectors who want to see cables laid underground rather than on pylons.
Speaking last year, she said consumers would "pay dearly" if the cables are not in place by 2019 and added that undergrounding would drive the project cost to £1 billion.
