The original directive was negotiated by the Labour Government in 1979. It is clear from that preamble that the entire rationale was built on the premise that the use of imperial measurement hindered trade. However, Mr. Thoburn and his market trader colleagues in Sunderland are not engaging in international trade. It is preposterous. If it was a question of concern for international trade, and a trader insisted on using a unit of measurement that was not acceptable to potential customers on the continent, he would not be able to trade.
People trade in the measurements that their customers want.
Friend is right. Trade exists by satisfying customers. Someone who supplies goods in units that are inconvenient or are not understood will not sell them. People do not need bureaucrats or central Government to tell them that. It is much better to leave such matters to normal commercial intercourse at market level.