Peter,
Believe it or not your Dad’s policy has done quite well for such a low premium. You say it is with a UK company but you talk in euros so I presume the policy itself is Irish. As such it would be under a previous tax regime which levies 20% tax on any profits inside the policy and no tax on surrender or claim. On tax grounds alone I would keep it in force. There does not seem to be any “insurance” element any more, it is purely a savings plan. As I say on tax grounds I would keep it in force but neither would I disagree with SBarrett’s advice to cash it in, realising the proceeds will earn no interest these days.
Further thoughts, there are probably policy fees which on such a small premium would negate the minor tax advantage, so on balance I would cash it in.