Normally we carry a copy of our passports with us all the time, but on this particular afternoon my hubby hadn't taken his 'man bag ' with him which contains a copy of his passport, so they accepted his EHIC card that I keep in my purse.
I asked them why this has now become necessary, and they told me it was a government initiative to fight counterfeit cigs/ tobacco.
I opened a carton of cigs to take out a couple of packets the day before we came home, and I placed the carton in my hand luggage.
At Malaga airport after my bag had gone through the screening, they stopped me and opened up my bag to inspect the opened carton of cigs for the tax paid sticker on every packet.
Whilst rummaging through my bag, he asked me if I'd bought them in Spain. I had kept the receipt handy in my pocket and after showing it him, he was fine about it.
So, it seems that if you want a receipt, you now need some form of identification, and if you've got tobacco in your hand luggage keeping the receipt at hand in the airport is recommended.