6 months...

If the person has a valid foreign passport and an expired Nigerian passport you are allowed to travel. Mine was expired and I had no issues. According to IATA you are allowed to. Had no probs in July

chaircover: Pls How many months does one need left on their Nigerian passport to be able to travel out of the UK?

Is it 6 months
3 months
Or at the airlines discretion?

Some years ago i had 4 momths left and the airline was acting funny, but they eventually let me go, but I dont know what the procedure is now.

Thanks

There is no limit, you can travel (even with an expired passport) as long as the visa in it is still valid, but if you are travelling to a visa-free country, you can use an expiring passport provided you can prove (from your onward or return ticket) your intention to leave the country before the passport expires

chaircover: Thanks everyone for your responses

Sorry I wasnt clear enough in my OP

This passport doesnt have any visa. The passport holder has dual nationality

ie British and Nigerian and uses both to travel in and out of the country.

The Nigerian passport is the one I am asking abiut

Like I said, as long as the person's got one valid foreign passport that person is ok to go, he or she should just present the expired one to naija customs.

If the person does not feel comfy then he or she should get a visa.....but for me ooo I know it is very legal cos mine was expired and had no visa stamp.....even the airlines will tell you, they go through one international check and it states there that it's no problem

chaircover: Thanks everyone for your responses

Sorry I wasnt clear enough in my OP

This passport doesnt have any visa. The passport holder has dual nationality

ie British and Nigerian and uses both to travel in and out of the country.

The Nigerian passport is the one I am asking abiut

I thought you were talking about travelling to Europe with an expiring passport, now I see you meant travelling to Nigeria with such.
Well, by rights, you do not need a valid passport to enter Nigeria, all you need is a proof of nationality, and an expired passport is a valid proof of that.
But unfortunately, we have immigration officers who are happy to use any excuse to zap money out of travelers, even if that means infringing your fundamental rights.
In normal countries, immigration officers are happy to welcome their citizens who are returning home(even a driver's license or birth certificate are enough to let them in), but not so with the Nigerian immigration officers: these wicked beings are ready to make you spend 10 hours at the airport just to frustrate you and bring you to comply with their demands