Sir Keir Starmer knows the £2,000 tax hike row is cutting through (2024)

The political truce put in place for the D-Day commemorations was shattered yesterday as Sir Keir Starmer climbed off a landing craft in Portsmouth and told reporters Rishi Sunak was a liar.

Why was the normally mild-mannered Labour leader so cross?

Because the previous evening he had allowed the PM to land his first big blow of the election campaign by failing to challenge his claim Labour's plans will cost the average family £2,000 in extra tax.

During Tuesday night's ITV debate, Mr Sunak could hardly believe his luck as he was able to raise the claim a dozen times without serious push-back.

Labour strategists became so alarmed that an aide was sent to speak to Sir Keir during the break. Only then did he finally describe the claim as 'absolute garbage' – and even that, in the lexicon of Westminster, is not a denial.

Belatedly realising the threat, Labour attack dog Jonathan Ashworth was sent out yesterday morning to dismiss the figure as a 'lie'. By the afternoon, Labour concern that the figure was taking hold was so great, the leader himself decided to repeat the incendiary charge as the nation marked the 80th anniversary of D-Day.

The problem for Labour is that the £2,000 figure is not easily dismissed as a 'lie'. It is based on a document released by Chancellor Jeremy Hunt in May following months of work by Treasury officials. The dossier analyses 27 tax and spending commitments made by Labour and identifies a 'black hole' of £38.5billion. The bill is equivalent to £2,094 per working household over four years.

Treasury costing of Opposition policies has been common practice for 40 years and was regularly deployed by Gordon Brown.

Some of the assumptions used are provided by political advisers in the Treasury. But in this case they appear to have erred on the side of caution. For example, officials could have based the cost of Labour's proposal to provide free school breakfast clubs on 100 per cent take up. Instead they have assumed that only half of all children will take advantage, costing £1.5billion a year by 2028. Labour has not provided a figure itself.

Labour yesterday seized on a letter from Treasury Permanent Secretary James Bowler distancing his officials from the figures.

It is true that not all of the data came from the Treasury – although most did. Totting up the cost over four years is also a tactic unlikely to meet with approval from impartial civil servants. The £2,000 figure is based on an average of £500 a year over four years. Sharp political practice, perhaps, but not a 'lie'.

Lord O'Donnell, who served as permanent secretary to the Treasury under Mr Brown, described the practice as 'one of the grubbiest processes I've ever been involved in'.

It is no surprise to hear Whitehall mandarins describe the political process as 'grubby'. But that doesn't mean the £2,000 figure is not a useful pointer to the fact Labour may have dramatically underplayed the true cost of its plans.

And judging by Sir Keir's panicked reaction yesterday, he already knows it might stick.

Debate viewing figures down on Boris v Corbyn

The first head-to-head TV debate between Rishi Sunak and Sir Keir Starmer was watched by an average of 4.8 million viewers, down by more than two million on the 2019 equivalent.

Tuesday night's showdown, which saw combative exchanges on issues such as tax increases and immigration, aired at 9pm and lasted for more than an hour. But the audience fell far short of the nearly 6.9 million who had watched Boris Johnson lock horns with Jeremy Corbyn in the 2019 opening TV debate, also on ITV.

TV election debates became part of the political landscape in 2010, when the first of the televised exchanges attracted nearly 10 million viewers.

Rishi SunakITVLabourKeir Starmer