The Council of Trade Unions says a major supermarket chain in the United Kingdom is weighing into a pay dispute at the CMP Rangitikei meat processing plant.
Since negotiations over proposed pay cuts broke down on 19 October, 111 workers at the plant have been locked out.
CTU president Helen Kelly says the CTU has received an email from the supermarket chain Waitrose urging the plant's owners, ANZCO, to resume mediation with workers.
Ms Kelly says the largest union in Britain, Unite, has threatened to picket Waitrose stores selling ANZCO products until it returns to the negotiating table.
She says if ANZCO continues to lock out workers it will threaten New Zealand's brand image in Britain as an ethical producer.
ANZCO could not be reached for comment.
