The 15 per cent payout works out at between £206 and £245 depending on the iMac configuration.

The cheapest 27-inch iMac listed on the UK Apple Store is £1,378, the higher spec Quad Core option is £1,634. Both are showing 3 weeks for shipping, a timescale introduced before Christmas.

On Monday, Apple released the , which promises to "address issues that may cause intermittent display flickering" iMacs.

This latest firmware update doesn't appear to address the yellow tinting appearing at the bottom of some iMac screens, although for many the update appears to flickering screens issues.