UTV has been accused of trying to "shaft and sideline" the smaller political parties by proposing to screen their leaders' election debate shortly before midnight.
The heads of the five main parties secured a 9pm prime time slot for their hour-long showdown last Thursday on the channel. But TUV, People Before Profit and the Green Party have criticised UTV for originally proposing that their half-hour leaders' debate be screened at 11.40pm this Thursday.
TUV leader Jim Allister said: "It was an outrageous attempt to shaft and sideline us. Such an attitude is very disappointing at a time when the electorate is angry at the bigger establishment parties, and receptive to the idea of change."
Mr Allister said his party joined forces with People Before Profit and the Greens, with the trio threatening to pull out of the debate altogether if they weren't offered a better slot.
UTV came back with a proposal that the debate be shown at 10.40pm this Friday, which the parties agreed to, the TUV leader revealed.
A UTV spokeswoman said last night: "Following consultation with the smaller parties last week, we have secured a new time slot of 10.40pm in our schedule this Friday evening, which is the same time as 2016 for this smaller party leaders' debate. Our election debate coverage and timings are in line with regulatory guidance."
Mr Allister will take part in the debate along with People Before Profit's Eamonn McCann and Green leader Steven Agnew.
Mr Allister said: "UTV's original proposal diminished and demeaned us. A screening which ended after midnight on a day when people have to get up for work in the morning would inevitably have failed to secure a wide audience.
"The 'cash for ash' scandal has led to a fluidity in politics here which we haven't seen in a long time, so it's particularly disgraceful that we were being denied the chance to have our debate shown at a reasonable hour."
Mr Agnew said: "We're disappointed that we had originally been demoted compared to previous years, given that this time the Greens are standing in all 18 constituencies across Northern Ireland."
Mr McCann commented: "I welcome that UTV has had a change of heart.
"But I'm not surprised that the smaller parties were initially offered such a late slot. The entire system, in Stormont and outside it, greatly favours the five big parties."
Last Thursday's debate on UTV was watched by an average of 141,000 people - 23% of total viewers - with a peak audience of 162,000. Last year's debate was watched by an average of 99,000 people, or 18% of the total audience - peaking at 128,000.
UTV Smaller Parties Election Debate, Friday, 10.40pm.