Former Virginia Gov. George Allen issued a e-mail to supporters shortly after noon today announcing that he will officially announce later today his candidacy for the GOP nomination to run for the U.S. Senate in 2012. Allen lost a bid for the same job to Democratic U.S. Senator Jim Webb in 2006, who is expected to seek reelection to a second term next year.

However, conservative Republican activists are already signaling that Allen will face stiff opposition for the nomination of his party. An email issued from Ed Schultz late this morning indicated that prominent Virginia conservative Erick Erickson, operator of the influential RedState.com blog, has endorsed state Tea Party leader Jamie Radtke of Richmond for the job. Radtke, who has announced her candidacy, is a graduate of Liberty University and was chair of the Richmond Tea Party and the chair of the Federation of Virginia Tea Party Patriots.

Other potential candidates seeking the GOP nomination are State Del. Bob Marshall and Prince William County Board Chair Corey Stewart.