To say ''In a pigs ear, it is!'' meant 'not bloody likely!' Or, depending on context, it expressed irony/and/or disbelief. Where I now live, in Northumberland, I've often been told-off for using this expression as it is regarded as 'bad luck' to mention the word 'pig', especially so nearer the coast. They are refered to as 'guffies' or 'articles'. Which reminds me, back in the Black Country, my parents often affectinately called me a 'daft article' if I did somehing foolish...perhaps, on reflection, they were just calling me a stupid pig?!?!?!?