A U.S.-based retail chain, 7-Eleven, is calling for customers show their presidential preferences early by ordering hot beverages in cups indicating their allegiance.

Those supporting Republican candidate John McCain can support him by choosing Republican red cups while those preferring Democratic nominee Barack Obama should opt for Democratic blue ones.

Undecided or abstaining patrons in need of coffee can use a regular 7-Eleven cup, reports the Dallas News newspaper.

The promotion, which starts on Wednesday and ends Election Day, mirrors events the chain launched for 2000 and 2004 presidential elections.

While the company doesn’t claim the poll is scientific, on both previous occasions cup voting was close to official surveys and the final election results.

Cups are registered instantly when the purchase is made. The retailer is to update interim results daily on the official website.