Actually, the government was not involved. The change was proposed by a retailer.
Not mentioned was the wholesale price of the razors. If the wholesale price is different then the retailer is foolishly taking a loss. If the wholesale price is the same then the parity has some merit
You make money buying, not selling
From the article excerpt:
Tesco said it had come under pressure from British lawmaker Paula Sherriff
If the retailer has come under pressure from a 'lawmaker' (who is evidently an 'MP') then it can be fairly said that the government was involved.
Company says it was pressured by an MP.