WASHINGTON — With burgers as ballots, a restaurant in the US capital is conducting its own gourmet straw poll in the run-up to national elections on November 6.

BLT Steak, a stone's throw from the White House, is giving patrons a choice of hamburgers named after President Barack Obama, Vice President Joe Biden, Republican challenger Mitt Romney and his running mate Paul Ryan.

Voting ends October 2, just over a month before polling day.

The Obama burger is the most expensive at $28 because "he's the president" and deserves the best, manager Adam Sanders -- whose establishment counts the first family among its patrons -- said on Tuesday.

It combines eight ounces (225 grams) of American-produced Kobe style beef with a roasted pineapple, in what Sanders called a homage to Obama's Hawaiian roots.

The Romney burger features a similar-sized patty with a "Utah style pastrami stack" -- Utah is the home state of the Mormon faith, to which the former Massachusetts governor adheres -- and Swiss cheese. It costs $23.

For Biden, the restaurant came up with a $23 saucy Sloppy Joe, while the slightly pricier $26 Ryan burger is topped by cheddar cheese from his native Wisconsin.

For the undecided, there's a double-patty BLT Monument with bacon, lettuce, tomato, cheddar cheese and onion rings -- a relative bargain at $18.

"The Romney burger seems a little bit kind of weird," said Eddie Vale, who works at the AFL-CIO labor federation, just around the corner from BLT Steak, after tucking into his "All-American" Obama burger.

Another diner, Tim Tagaris, opted for a Biden burger "because Swiss cheese has no business on a cheeseburger" in the United States, while Jessica Morale said: "I'll never order a Romney burger -- it's against my morals."