@Gingerrogered
We used to get the harvest in without EU migrants before we joined the EU
No, since the Industrial Revolution the UK has struggled to get sufficient seasonal labour to work in agriculture - as I have explained in the post above.
Yes, it was a student exchange scheme. I'm not really sure how posting details of a scheme which saw students pick fruit somehow disproves that short term seasonal workers could be found if necessary
Sufficient seasonal workers could not be found in the UK, hence the 1945 Scheme, which started off as a scheme for students but almost immediately had to be opened to others as there were not sufficient foreign students applying. The 1945 scheme was necessary despite there being 400,000 POWs and 200,000 Eastern European refugees working on UK farms at the time - the POWs as forced labour.
offer them an opportunity to pay off some of their fees or save for a gap year by working and they'll get very cross
Many students, myself included, have worked on farms during the summer. It was backbreaking work for little money. The truth is that farm labour has been treated appallingly for years - as recently as 2005 the government had to set up the Gangmasters and Labour Abuse Authority in an attempt to improve conditions for agricultural workers, but there is still evidence of exploitation by farmers and gangmasters and little in the way of unions or organised labour in the industry. The government departments tasked with ensuring that rules regarding working conditions, minimum wages etc. are adhered to are the Border Force and police (i.e. the Home Office) and HMRC. A certain Mrs May has taken great delight in cutting the size of these organisations, making them almost ineffective in this area.