The Food Standards Agency has said it will continue testing products "until there's nothing left to find" after the veterinary painkilling drug phenylbutazone - or bute - was found in Asda Smart Price Corned Beef.
The agency's director of operations Andrew Rhodes said customers should not eat the corned beef but added anyone who does is very unlikely to fall ill.
He advised customers to return the product to the supermarket to receive a full refund.
More top news
The former prime minister made the comments as he prepares to return to politics saying he wants to be "part of the debate" on Brexit.
The new measures would mirror childcare vouchers and see workers sacrifice some of their salary to benefit.
Google, Facebook and Twitter could face multi-million pound fines over their failure to remove illegal content, MPs say.