British workers will be poorer by an average £2,500 a year by 2031 because of the ~ impact of immigration driving down salaries, a new analysis has concluded.

According to calculations made by the Conservatives -using figures provided by the Office for Budget Responsibility (OBR) and the Bank of England - immigration will cost UK staff a total of £89.8 billion in suppressed wages over the next five years, with the average worker £2,521 a year worse off.

It comes as the issue of mass migration has risen to the top of the political agenda again following the arrival of 60,000 African migrants into the Spanish territory of Ceuta last week, the biggest ever one-day surge of illegal migrants into the EU.

Separately, 752 migrants reached the UK on Wednesday alone - the highest number of Channel crossings in a day so far this year.

Reform UK's home affairs spokesman Zia Yusuf travelled to Ceuta yesterday and described the surge as 'an invasion, plain and simple...these people are marauding through town, looting shops and terrorising local residents. I have spoken to a number of them who made it quite clear they intend to make it to Britain.

'One even admitted that they're wanted for murder in their home country.' 

Spain condemned the 'selfish, polarising and unlawful' reaction of some EU countries to the influx, saying that almost all of those who reached Ceuta on Thursday have since returned.

The Tory wage projections are based on OBR forecasts that between 2026 and 2031, cumulative net migration will total around 1.4 million, increasing the competition for jobs and placing downward pressure on wages.

The Bank of England calculated that a 10 per cent rise in the immigrant-to-native ratio in a given occupation and region is associated with a 0.93 per cent reduction in average wages. It means that average annual earnings are projected to fall from £38,220 at the baseline to £35,699 by 2031.

Shadow home secretary Chris Philp called for a binding annual cap on inward immigration and a tightening of visa rules.

He said a Conservative government would attach new conditions to Indefinite Leave to Remain (ILR) status, and extend the time people must wait to apply for British citizenship from 12 months to five years after obtaining ILR.

Mr Philp said: 'High immigration has real consequences across our whole society, and British people feel indirectly in how much they earn. Labour have opened the door without any plan to deal with the consequences.

'The next Conservative government will introduce a binding annual cap, close the loopholes that let temporary visa holders stay indefinitely, tighten the conditions for ILR, and extend the period required.

'Sadly, Labour don't have the backbone to do any of this.'

Mr Yusuf added during his visit to Ceuta: 'Unless we secure our borders, then we are going to see scenes like the ones we have seen become sadly increasingly common and the people who suffer most from all of this are the hard-working British people.

'Only Reform UK has the courage to detain and deport all illegal migrants.'