A Virginia Republican lawmaker is criticizing his state party for requiring primary voters to sign a so-called loyalty oath in order to vote in the March 6 presidential primary. 

The state's Board of Elections approved the proposal earlier in the week. Going forward, voters who arrive at polling sites in March will be required to sign the following statement: 

"I, the undersigned, pledge that I intend to support the nominee of the Republican Party for president." 

The idea is to keep out impostor Republicans, given that Virginia has an open primary, meaning voters of all political stripes, not just Republicans, can participate in the party's presidential primary. 

But Robert Marshall, a state delegate, told Fox News the plan effectively would require residents in some cases to commit to a candidate they're not yet familiar with. 

"For the Republican Party to depart so far from what the founders wanted, I think, is a mistake," he said. 

It's not the first time the state GOP has made voters pledge their allegiance. Back in 2000, they had voters sign a pledge saying they wouldn't participate in the nominating process of any other parties. The latest measure is more strict -- even though it is not enforceable and anybody who breaks the pledge will face no punishment. 

According to the Richmond Times-Dispatch, even absentee voters will receive a notice to inform them of the pledge. 

Meanwhile, Virginia's presidential primary ballot currently only includes two candidates -- Ron Paul and Mitt Romney. The rest did not meet the state's signature requirement, though the other candidates are challenging their exclusion in court.