Hundreds of thousands of viewers are expected to tune into the first television debate of the general election campaign when it is broadcast tomorrow night.

First Minister and SNP leader John Swinney, will take part in the event along with the opposition party leaders Douglas Ross, Anas Sarwar and Alex Cole-Hamilton in the STV Leaders’ Debate at 9pm.

The programme will see STV political editor Colin Mackay grilling the leaders of Scotland’s four main political parties.

Mr Mackay will question each leader at STV’s Pacific Quay headquarters in Glasgow before they cross-examine each other.

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Following the debate, Scotland Tonight presenter Rona Dougall will be joined by a panel of guests to provide instant reaction and analysis.

The STV Leaders’ Debate is the first of two televised debates airing on STV next week. A head-to-head between Rishi Sunak, leader of the Conservative Party, and Sir Keir Starmer, leader of the Labour Party, will follow at 9pm on Tuesday, June 4.

Brian Taylor, a columnist for the Herald and BBC Scotland's former political editor, said televised debates are a chance for the parties to put across their main messages to a wide audience.

“Contrary to the hopes of candidates, people are not engrossed in elections every second of their busy lives.  They garner information where they can – and where it is presented to them in an accessible format.  

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"Now, that might be newspapers or online news sites or social media.  
“But, frequently, it is via the airwaves, the telly and the wireless.  Broadcast debates often have two functions:  they allow parties to ventilate their key messages and they allow cross-examination, either from rivals or from broadcasters," he said. 

“Parties will be content if they get across a key policy.  But they will be delighted if they contrive to sidestep the perils and pitfalls of broadcast discourse.  

“There is another issue. The leading contenders often want to go head to head, in a Presidential-style debate. Understandably, other parties want a say. As this election is proving, that dichotomy has yet to be successfully resolved.”  

Some 458,000 people watched STV's 2019 debate featuring Scottish party leaders ahead of that year's general elected, while the SNP leadership debate shown by the broadcaster last year featuring Humza Yousaf, Kate Forbes and Ash Regan reached 600,000 viewers.

Ahead of the debate, the Herald on Sunday asked the parties taking part what they would be focusing on.

Scottish Conservative Chairman Craig Hoy MSP said: "The election in Scotland is about beating the SNP and ensuring the focus moves onto people's real priorities.

"In key seats up and down Scotland, it is only the Scottish Conservatives who can defeat the SNP and help to end their independence obsession for good.

"The Nationalists will always put party before country, whether that's plotting to break up the UK or defending their disgraced colleague Michael Matheson.

"If voters unite around our party, then the focus will be on the real challenges facing Scotland such as reducing NHS waiting times, creating good jobs and growing our economy, rather than nationalist MPs pushing for independence."

Scottish Liberal Democrat leader Alex Cole-Hamilton MSP said: “I am very much looking forward to this debate.

“Elections aren’t won or lost on a TV debate, but this is a chance to pitch our message of hope and change to the people of Scotland.

“With every Liberal Democrat you elect, you will get a local champion who will work tirelessly for you all year round and put public service at the heart of everything they do.”

Linda Grimes Douglas, head of news and current affairs at STV, said: “Ahead of major votes like the forthcoming General Election, we know many viewers value having the opportunity to hear political leaders set out their plans for the country and debate the issues that matter most to the electorate.

“STV is pleased to be broadcasting the first leaders’ debate of the election campaign. An in-depth and robust head-to-head, it will likely set the agenda for the coming weeks in Scotland.”