Poll shows Obama and McCain in virtual tie

Presumptive presidential nominees Senator John McCain and Senator Barack Obama are shown in this combination of file photographs from campaign stops from July 18, 2008 in Warren Michigan (McCain) and August 4, 2008 (Obama) in Lansing, Michigan.

WASHINGTON (Reuters) - Democratic presidential candidate Barack Obama leads Republican John McCain by 47 percent to 46 percent, a statistical dead heat, in an NBC News/Wall Street Journal poll released on Tuesday.

Obama's lead is down from his 3-point advantage in August and a 6-point edge in July, NBC said on its website.

The survey was taken from Saturday to Monday and had a margin of error of 3.3 points. The findings were similar to other polls showing a tightening race since the Democratic and Republican conventions.