What is a parliamentary ‘supermajority’ - and can Labour even win one?

It’s the main word being pushed by the Conservative Party in the final days of the election, as polling consistently hints at a major defeat for the governing party, but what exactly is a “supermajority” which the Tories are warning of when it comes to the likely win for Labour following Thursday’s big vote?

Speaking to campaigners at a rally on Tuesday, Prime Minister Rishi Sunak insisted the outcome of this week’s election for his party is “not a foregone conclusion”.

“If just 130,000 people switch their vote and lend us their support, we can deny Starmer that supermajority.

“Just think about that: you have the power to use your vote to prevent an unchecked Labour government,” he said.

Meanwhile Labour leader Sir Keir Starmer told The Times that a “strong mandate” is required in order for him to reform the planning system and boost the economy, and that a bigger majority is “better for the country”.

“Because it means we can roll up our sleeves and get on with the change we need,” he said.

So, to echo comments made by Lord David Cameron: what is a supermajority anyway?

Yep, not even the foreign secretary has a clue what the phrase means, as he conceded to Channel 4 News last month: “I’ve never even heard of the phrase ‘supermajority’ … It doesn’t actually exist in the UK.”

And unlike his prediction on how the 2016 EU referendum would turn out, Lord Cameron isn’t wrong, as it’s a more popular term in the US to denote a backing of two-thirds for a particular vote.

It doesn’t quite match up with the UK parliamentary system, because that is never reliant on a two-thirds majority for a vote to pass.

Instead, with a total of 650 seats up for grabs on Thursday, a party needs only 326 MPs (so 50 per cent, plus one) to have a majority in the House of Commons.

When this isn’t reached, there’s a hung parliament and it’s up to parties to form coalitions to reach that magic number - such as the Tories’ coalition with the Liberal Democrats from 2010 to 2015, or the “confidence and supply” agreement reached between Theresa May’s Conservatives and the Democratic Unionist Party (DUP) in 2017.

But when a party has a majority, it’s easier for legislation to pass.

As the Electoral Reform Society notes: “When it comes to Westminster, a party with a majority of one can legislate on anything it likes, as long as it can keep its backbenchers in line, just as a party with a ‘super-majority’ can. A massive majority doesn’t grant any extra privileges or powers.”

The Institute for Government makes a similar point in its article on the Tories’ “supermajority” talk, writing that “in parliamentary terms the difference between an 80-seat and 200-seat majority is not material”.

Of course, the lower the majority, the fewer number of government rebels required by opposition parties to stop a particular bill from progressing, but even then, the governing party is rarely defeated when it comes to passing legislation – the last time that happened in a bill’s final stage was back in 1977.

A greater – and indeed, more legitimate – concern from the Conservatives about a large majority for Labour would relate to the cross-party select committees, with memberships and party splits reflecting the composition of the Commons as a whole.

As such, a significant majority for Labour would mean more of its own MPs in select committees holding the government to account, and although these committees are cross-party (and therefore still critical of ministers), naturally the Tories would want to see more of their politicians in these groups.

With polling day taking place on Thursday, it’s obviously not known for definite who will form the next government – but consistent polling has made it pretty clear that Starmer will be the next PM, with YouGov predicting 425 seats for Labour (an overall majority of 99) and Survation giving the party 484 seats, or an overall majority of 158.

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