Birmingham Assay Office opened a base in Mumbai this year where it uses the anchor as its mark of certification for jewellery and also plans to use the same once it sets up a base in Jaipur.
However, some Birmingham-based jewellers launched an online petition recently on the UK government website, demanding that it not be allowed to use the identical mark.
"Hallmarks by assay offices located overseas should not be identical to UK marks," reads the headline of the petition, which has so far received over 1,500 signatures.
At 100,000 signatures, it would have to be considered for parliamentary debate in the House of Commons.
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"In 2013 the four UK Assay Offices were allowed to open up sub-offices in other countries. The intention was that 'offshore' assayed items would carry a different hallmark. Birmingham Assay Office in Mumbai, India, are using Birmingham hallmarks identical to the UK marks. This misleads the consumer," the petition says.
London's Assay Office uses a leopard's head, Edinburgh's a castle and Sheffield's a rose. The symbols denote the office that marked the item as a seal of authenticity.
The British Hallmarking Council confirmed the law allowing assay branches abroad did not state that a different symbol must be used.
More than 90 per cent of jewellery sold in Britain is made abroad.
Before the opening of the Birmingham office in Mumbai, manufacturers had to ship items to the UK to be hallmarked then return them to India to be completed and re-exported.
John Langford of London silversmith and jewellers Braybrook & Britten, who launched the petition, told 'Antiques Trade Gazette' that allowing items to be stamped "off shore" in this way would "downgrade" the whole market.
"To apply an identical UK hallmark, in another country well beyond UK legal jurisdiction and without the added oversight of such bodies as Trading Standards and the National Measurement & Regulation Office, is to mislead the consumer. It is no longer a UK hallmark," Langford added.
However, the Birmingham Assay Office maintains that its hallmark is a "guarantee" of quality anywhere in the world.