Updated

Republican Mitt Romney's campaign has sent letters to election officials in Wisconsin, Mississippi and Vermont demanding that the deadline for receiving ballots from military and overseas voters be extended.

The letters sent last week and Monday on behalf of the Romney campaign by former U.S. Veterans Affairs Secretary Anthony Principi say election officials in each of the states missed the Sept. 22 deadline for mailing some ballots to overseas and military voters.

Romney campaign spokesman Ryan Williams says a fourth letter was to be sent to Michigan officials on Tuesday.

A spokesman for Wisconsin's elections board says 44 ballots were mailed to military and overseas voters within five days after the deadline.

Romney's push is part of a broader effort to court the veterans vote.