The first blasts Labour over Sir Keir Starmer’s stance on immigration and small boats pact with the European Union.

However, another highlights concerns about the threat from Reform UK.

It said: “The more people who vote Reform, the greater chance we end up with an anti-Brexit MP who didn’t respect the view and the vote of the vast majority in our area.”

Habib is also fixating efforts on disillusionment on border control as a recent YouGov opinion poll revealed immigration is the most important issue for Brexit-backing and Tory voters.

However, immigration features much less prominently on Labour’s by-election literature.

Kitchen’s campaign instead centres on issues such as the NHS, knife-crime, potholes, cost-of-living and political integrity.

Chesterfield MP Toby Perkins and Shadow Defence Secretary John Healey suggested fatigue with the Tories is instead fuelling support for Labour.

Perkins told GB News: “This isn’t a mid-term protest vote. This is people making serious decisions.

“But we are conscious that this is not a seat that is on the list that Labour has to win in order to win the general election.”

Healey added: “Many people are saying time is up, time for a change.”

North Northamptonshire, which covers Wellingborough, is roughly in line with England’s overall demographic shift.

Eight-in-10 residents reported their country of birth as England, data compiled by the Office for National Statistics has shown.

However, Wellingborough witnessed a rapid growth in the number of births to non-UK-born mothers as a share of total live births.

The figure jumped from 20 per cent in 2010 to 33 per cent in 2019.

The speed of change can in part explain Wellingborough’s susceptibility to Ukip, Brexit and potentially Reform UK.

Ukip leapfrogged Labour into second place in 2015 after receiving 19.6 per cent of the vote and 64 per cent of residents supported Brexit just one year later.

Similar electoral shifts have been witnessed in Havering, Dartford, Boston, Thurrock, Swindon, Broxbourne and Mansfield.

Many of the seats had at some stage voted for Labour, particularly under Tony Blair.

However, voters in the constituencies seemed to shift towards Ukip and the Tories in the mid-2000s and 2010s.

Reform UK will hope to sweep up support over rising discontent with Sunak’s handling of both illegal and legal migration.

Net migration into the UK was a record 745,000 last year, revised figures have shown.

The Government is hoping to curb legal migration through a number of measures, increasing the minimum earnings threshold for Skilled Worker visas from £26,200 to £38,700.

A staggering 29,437 migrants crossed the Channel in 2023, down from the 45,774 who made the perilous 21-mile journey the previous year.

However, the Prime Minister was given a boost when his flagship Safety of Rwanda Bill passed through the Commons following a short-lived Tory rebellion threat.

Reform UK is ambitious about what it can achieve in Wellingborough.

The populist party is openly limiting expectations by claiming obtaining around 10 per cent support is the target.

A source told GB News: “The fact is that we are actually looking at hitting our average poll score in a fought by-election.”

“The Labour Party are everywhere, we can’t compete with that.

“By-elections are won in the trenches, street-to-street, on the ground. Labour have made a huge effort and I expect they will win.

“But we will save our deposit. I will be delighted if we hit 10 per cent and will be over the moon if we surprise the Tories and catch them.”

However, an activist on Wellingborough high street was keen to stress Reform UK is in it to win it.

Habib echoed the optimism, claiming: “The best result, and the result I am aiming for, is to win.”