The UK is seeking to renegotiate the Dublin Agreement in order to return more migrants back to France.
The incident took arrivals for April to more than 400 - the highest monthly total ever recorded.
The equivalent of 105,000 travellers land per week, including from hotspot nations such as China, Italy and the United States.
Migration Watch UK said that the Government should bolster efforts to encourage Britons into such jobs.
The news follows a drive to 'mobilise the British workforce' as global travel restrictions mean a shortfall in migrant workers.
Growers to recruit 70,000 laid off workers to harvest fruit and veg.