How Voluntary are Passports?

The Labour government are saying that asking passport renewals to get an ID card does not make it compulsory. But just how voluntary are passports.

OK if you don't want to travel overseas you don't need one. But with most internal flights being ticketless these days people are required to provide some form of photo ID either passport of driving licence. So I will need one to travel over to Northern Ireland to see my family for weekend visits etc.

I've just forwarded my mail having moved house. I had to provide two utility bills and my passport as ID.

I'm sure there are other criteria and occassions when a passport is acceptable ID, by itself, at present so why now do the governmnet insist that passports are volutary they already have far wider use than merely being to travel abroad. I hope the Lords stand up to the Labour Government in the Commons again following last nights further rejection of their reforms agaisnt this compulsion by stealth.