Sir Keir Starmer’s countless mentions during the election campaign that his father was a toolmaker became such a recurring theme that audiences began to laugh whenever he mentioned it.

On one such occasion, he retorted that when he was a young boy, his parents ‘couldn’t make ends meet, which isn’t a laughing matter’.

So, why, now he is Prime Minister, is this humble son of a ‘working person’ inflicting a punitive extra tax on Britain’s small businessmen and women just like his own father Rodney, who ran the Oxted Tool Company in Surrey?

Although Rodney Starmer died in 2018, toolmakers like him remain part of the backbone of this country’s engineering industry and are furious about the way their livelihoods are now threatened by tax rises in Rachel Reeves’ Budget last month.

The Chancellor announced a surprise hike in the National Insurance (NI) contributions that companies must make from next April – rising from 13.8 to 15 per cent – which the Institute for Fiscal Studies reckons will raise £17 billion for the Treasury.

Independent experts have warned that this could result in some firms going out of business. Steve Leigh, of the professional services company Aon, estimates that a small firm with ten employees each earning £35,000 a year will face a £9,200 rise in its NI bill, though other calculations are lower.

According to tax advice firm Blick Rothenberg, the total annual NI bill for employing such a worker will rise by 25 per cent.

Aamer Younis, manager of Henry Taylor Tools in Sheffield, South Yorkshire, is one of many toolmakers who will have to pay extra NI contributions.

Henry Taylor Tools has been making handcrafted woodworking pieces using local Sheffield steel – everything from chisels to wood turning gouges – since 1834. But now, Mr Younis, who manages a 13-strong team of craftsmen, is deeply worried about how such a proud heritage might count for nothing in the fight to survive.

He says: ‘If the Prime Minister’s father was a toolmaker, why is he not supporting us? We consider ourselves the Rolls-Royce of woodturning and wood carving tools, but this Government seems hell-bent on forcing extra tax burdens on our industry – while allowing foreign competitors to escape this unnecessary tax cash grab.’

Meanwhile, the NI threshold for employers has fallen from £9,100 to £5,000 a year – meaning that employers start paying NI on an employee’s salary at a lower level. However, the Government says it will support smaller firms who have an NI bill of under £100,000 by raising their employment allowance from £5,000 to £10,500. Around 865,000 employers are set to benefit – but Henry Taylor Tools is not one of them.

Robert Salter, a tax expert at Blick Rothenberg, says that despite only employing 13 staff, the Sheffield firm’s increased NI bill from April will cost at least an extra £2,000 a year.

Mr Younis says: ‘We are being squeezed by taxes every which way we turn – and this latest National Insurance contribution hike for businesses is only going to make it even more of a struggle to stay alive.

‘We cannot compete on price with cheap inferior tools made in China – and this hike will simply force prices up and make life harder for everyone.’

He adds: ‘We want the Government to support our call to buy British – not open the door to poor quality copies by foreign manufacturers that can fall apart in a couple of years rather than last a lifetime. We have two furnaces manned by three forgers with 30 years each of experience and skill.

‘It breaks my heart that industries like ours could be forced out of business with increased taxes and no support.

‘Why does Starmer not realise that knowledge passed down over many generations is priceless? Once firms such as ours are gone, the skills will be lost forever.

‘Starmer lives in an elite Westminster bubble far removed from the grimy reality of doing real work making tools. Did he learn nothing from his dad about our proud industry?’

Amanda Coffman, commercial manager of the Thor Hammer Company in Shirley, West Midlands, worries that the NI increase will hamper her firm’s ability to invest in new machinery and its workforce.

‘The increase harms prospects not just for ourselves, but the firms we work with, and also the whole British economy,’ she says.

Her 101-year-old, family-owned business relies on exports for about half of its trade – with the US its biggest market.

It employs three dozen staff to handmake top quality hammers, mallets and mauls for more than 50 countries. She says: ‘Foreign firms appreciate the quality of our tools but we need the Government to fight our corner because lower labour costs abroad mean we fight on an uneven playing field.

‘Our relationship with America will be especially important and Labour does us no favours with its recent criticism of Donald Trump and sending its staff members to campaign against him.

‘The Labour Government does not realise trade agreements are vital for business. If it lets us down, we face a desperately uncertain future.’

Ms Coffman adds that a typical toolmaker earns about £28,000 a year. Tax expert Salter says that based on this figure, Thor Hammer will be £14,869 a year out of pocket due to Reeves’ NI contribution rise.

The secret of the company’s success goes back to the Second World War when the RAF and Army used its tools to make and repair aircraft and tanks. This gave it an international reputation.

Katie Ellis is a director of the family toolmaking business Thomas Flinn & Co of Sheffield in South Yorkshire. She says: ‘We have heard an awful lot from Keir Starmer bragging about how he comes from working class stock – with his father a toolmaker and mother a nurse. But the way our industry is so badly treated, I get the feeling he has never got his hands dirty making tools.

‘Rather than taxing us out of existence, we want the Government to recognise toolmaking as people did when we began a century ago – the backbone of the manufacturing industry.

‘I am part of a third-generation, family-run business and we need people to be encouraged to roll up their sleeves and enjoy the reward of an honest day’s work.

‘It is a big challenge attracting younger people to learn our fabulous trade. We found our last apprentice a year ago on Instagram where he was showing how he was making guitars.

‘Why can’t the Government invest in apprenticeship schemes to get more people like him to realise toolmaking is such a rewarding trade? Instead, it clobbers us with an NI bill that is a disincentive to grow into a bigger company.’

Tax expert Salter says that, despite being a small company, Thomas Flinn’s extra NI bill will be £1,300.

Ms Ellis adds: ‘There is nothing old-fashioned about the toolmaking industry but it needs Government backing – not just more taxes to fund the public sector.

‘If we are to keep going and succeed in the future, we desperately need Government support. Starmer, as the son of a toolmaker, seems to have forgotten us.’