It has always been a tightly-guarded trade secret among London’s fish merchants.

And now the London Cure - the East End method for smoking salmon - has been awarded the same protected status as champagne, making London the first capital city to be awarded an EU protected food name.

Lance Forman, the owner and chairman of fourth generation smokehouse H Forman & Son, has been awarded the sought-after label for his London Cure smoked salmon.

It comes more than 120 years after his great great grandfather first opened for business at Billingsgate Fish Market, where the now-famous curing process was first perfected.

Congratulating Mr Forman on his achievement, Theresa May said the designation was a “fantastic” endorsement of “London and the UK food industry as a whole”.