There are several supermarkets that offer a euro travel money service.
Tesco offers the best euro rate of all the supermarkets.
If you want to get an up-to-date comparison of all travel money providers that provide Euros you can do so by using this link (Spoiler: Supermarkets are rarely competitive):
If you want to check out all rates which supermarkets offer, use these links:
Sainsbury’s travel money rates
Marks and Spencer travel money rates
Some people prefer to use a supermarket for buying their travel money, but rates are typically dreadful and are very rarely even in the top 10 of our comparison tables. Our advice is to shop around.