The Justice Secretary said his father’s business as a fish merchant in Aberdeen collapsed, partly as a result of Brussels rules.
But he was mocked on Twitter after stumbling over the names of two Scottish ports – referring to Peterborough and Fraserhead rather than Fraserburgh and Peterhead.
Answering questions following a speech on Brexit he said the common fisheries policy was a “symbol of what we lost when we entered the EU”.
He said: “Some in this audience might know that my father inherited a fish merchant’s business in Aberdeen from my grandfather and that business went to the wall, partly as a result of the common fisheries policy.
“The common fisheries policy essentially gave other European Union nations unfettered access to our fish stocks and – I would hope – that if we leave the European Union we can once more see the ports of Peterborough and Fraserhead and Grimsby flourishing, because we will take back control of our territorial waters.
“Fishing is perhaps not the most high employment industry in this country, but it’s a symbol of what we lost when we entered the EU.”