The NPA launched its Wall of Fame, which features brands confirming to source only pork products from farms that are compliant with the Council Directive 2008/120/EC for the protection of pigs.
NPA chairman Richard Longthorp claimed British consumers can be confident that most pork sold in Britain is traceable and sourced to high standards.
He said: "The response to our campaign for traceable higher-welfare pork for British consumers has been outstanding – far, far better than we ever envisaged."
Britain’s major food companies and retailers were urged by the NPA to check supply lines and boycott all pork sourced from illegally-operated continental farms.
NPA general manager Dr Zoe Davies said: "The response was slow to start with, but then ‘Horsegate’ erupted and food companies suddenly realised how vital it is that they know exactly where the raw materials they import come from.
"It is clear from the responses we have had that these companies have taken our challenge very seriously and, on behalf of British consumers, we thank them for their responsible stance," she added.
Davies confirmed that the NPA will continue to accept pledges and will start to conduct supply-line audits to check the pledges.
Meanwhile, recent figures from Brussels claim over 60% of European Union countries are not compliant with the sow stall ban that was enforced at the beginning of this year.