Stage set for tonight's ITV leaders' debate

from Peter MacMahon, ITV Border Political Editor in Salford

The stage is set, the podiums are ready, the leaders are doing their final preparations.

Yes, the ITV general election leaders' debate is nearly upon us.

My verdict two years ago was that Nicola Sturgeon was the strongest performer, doing better than David Cameron and Ed Miliband.

Post-debate polling showed the public broadly agreed, including voters south of the Border.

Though it must be said that after the two hours of exchanges none of the seven leaders made an election-losing gaffe, which was probably their objective.

I've been in Salford's Media City today as the final preparations are made for this latest debate and there is still some uncertainty as to who will turn up.

We know Nicola Sturgeon, SNP leader and First Minister, will be here along with the Lib Dem UK leader, Tim Farron, UKIP's Paul Nuttall, Plaid Cymru's Leanne Wood, and Caroline Lucas of the Green Party of England and Wales.

We know that UK Tory leader Theresa May has said she is not coming but we are not sure whether Labour leader Jeremy Corbyn will show up or not.

ITV is holding open a place for both of them until the very last minute.But if it turns out to be just the five, what will the dynamics be, and what should you look out for?

First, in the absence of a Conservative will Mr Nutall become the focus of attacks on the Tories - on the basis of the claim the Tories have borrowed many UKIP policies?

Second, how much will the other parties make of the fact the Prime Minister and, probably, the leader of the opposition at Westminster, are not there?

Will they keep mentioning it to draw voters attention to their claim that Mrs May and Mr Corby are afraid of debate?

Or will they make a brief mention and then use their time to expound their policies, and expose what they see are the weaknesses of the cases mde by their opponents who are present?

Third, how much will Nicola Sturgeon find herself under pressure on the SNP's record at Holyrood?

She will be the only politician on the platform who is in government, and has been at Holyrood for the last ten years.

In recent interviews, the First Minister has been asked about her government's record in areas like education - where literacy standards are falling - and health.

From Ms Sturgeon's perspective, she will want to spend as much time as she can making her case knowing that her party's main challenger in Scotland, the Tories, are not there to answer back.

And the First Minister will want to appeal if she can to voters south of the Border, to make the case that her MPs, if elected, will support 'progressive policies' at Westminster.

Ms Sturgeon will not, however, be enthusiastic about a 'progressive alliance' at Westminster to keep the Tories out of power.

Having floated that idea, which was the SNP policy at the last UK election, she quickly explained it was not going to happen because, in her view, Labour would not get enough seats to make it possible.

Another aspect to watch will be the nationalist/unionist dynamic.

Ms Sturgeon and Ms Wood are likely to be supported by Ms Lucas in their nationalist outlook.

The Greens in England and Wales are a separate party to the Scottish Greens but broadly supportive of their Green colleagues north of the Border who back independence.

For Mr Farron the challenge is to reach out to a UK audience amid signs his party is having to work hard to make the breakthrough it hopes for.

He will also have to take on Ms Sturgeon from time to time as the Lib Dems hope to take seats from the SNP in Scotland.

The previous debat attracked an audience of well over seven million people, so the politicians know there's a lot at stake.

I'll be watching and analysing the exchanges. I'd suggest it's worth a watch tonight at 8pm on ITV.