Members of Minnesota's congressional delegation are asking the federal government to put the brakes on a plan to move an immigration agency to a new Bloomington location that could prove inaccessible to many people who need it.

U.S. Sens. Amy Klobuchar and Al Franken and U.S. Rep. Keith Ellison also introduced legislation that would prevent the U.S. General Services Administration (GSA) from making the same mistake again.

The GSA has signed a $14 million contract to move the U.S. Citizenship and Immigration Service from its current location near the Mall of America 11 miles to the west to a new building in Bloomington bordering Eden Prairie.

In violation of its own policies that require easy access to public transportation, the new building will be 3 miles from the closest bus stop. The GSA has admitted it misread a bus schedule in reviewing applications.

The move, which is expected in September, has raised the ire of immigration attorneys and advocates, who say many of their clients rely on public transportation to get to the center.

The legislation, authored by Klobuchar and co-sponsored by Franken, would require the GSA to verify that any building location meets public transportation distance requirements specified in its lease solicitation, and that public transportation runs regularly throughout the normal business hours of the building.

Klobuchar, Franken and Ellison also joined with Democratic Reps. Collin Peterson, Betty McCollum, Tim Walz and Rick Nolan in sending a letter calling on the GSA to halt the proposed move in Bloomington.

The letter asks the GSA to indicate whether it has explored alternative locations with adequate public transportation and whether it could use space at an old location that the U.S. Immigration and Customs Enforcement (ICE) is vacating. It also asks how much it might cost to vacate the lease of the new building, and whether another federal agency might use the space instead.

"With important questions still outstanding, we urge you to halt the current plans for relocation and to explore alternative locations that include adequate public transportation options," says the letter, which asks for answers by Friday.

The Minnesota USCIS office serves all of the state as well as the Dakotas and a large swath of western Wisconsin. Last year it saw about 28,000 people who scheduled interviews, used its information center or came to pick up citizenship certificates. It processed more than 13,000 applications for naturalization in 2013.