The Corn Laws were measures enforced in the United Kingdom between 1815 and 1846, which imposed restrictions and tariffs on imported grain. They were designed to keep grain prices high to favour domestic producers, and are considered examples of British mercantilism.
The Anti-Corn Law League was a successful political movement in Great Britain aimed at the abolition of the unpopular Corn Laws, which protected landowners' interests by levying taxes on imported wheat, thus raising the price of bread at a time when factory-owners were trying to cut wages.
The league's leader, Richard Cobden, was able to influence the prime minister, Sir Robert Peel. The failure of the Irish potato crop in 1845 persuaded Peel to support the repeal of all Corn Laws, which was achieved in 1846
Just a quick google, history was probably my shakiest subject and DH is not here to consult 
So it was a form of protectionism.
At the moment a lot of chicken used in ready meals is, I believe, produced in Thailand and some in Brazil.