Why on Earth would the government need to get involved? The market is working as it should freely already without any government interference.
The idea a product both made and sold in the UK using British ingredients needs a 10% cost increase due to currency changes is a nonsense and their former Director who ran the company until 2014 and now runs their biggest customer in Tesco's knows that and called their bluff. Now they will negotiate and a more reasonable compromise will be reached. Without any government interference whatsoever.
I bet you there won't be 10% increases though in the end as it's simply unnecessary.
Well, we'll never know what kind of agreement they reached. But since Unilever does publish its company results in Euro, I don't think it's such an easy task as you make it out to be.
When the stars threw down their spears
And watered heaven with their tears:
Did he smile his work to see?
Did he who made the lamb make thee?