I'm of the view that it should be the pilots choice, along the lines of a BFR in the States.
Most pilots will have the sense not to fly if they are un-current, I certainly don't, the longest gap I've left is about 7 months. I went up with an instructor until I felt happy (a couple of hours and some circuits), he was happy, and I went on to complete a further 100 or so hours over the next 10 weeks. I now try and fly every couple of weeks, but have trouble finding flying buddies....my mates work too hard, and I get bored flying on my own
(EGHH...TB10/PA28.....loads of hours to burn if anyone wants a jolly sometime)