If he becomes mayor, Comptroller Bill Thompson’s plan for closing the city’s $5 billion budget deficit is to hit up “a friend in Washington” — President Obama.

“The mayor needs to go down to Washington and start to work with the legislative leaders and the Democratic president to generate additional dollars in a few places,” Thompson declared at a Crains New York Business breakfast yesterday. “We have a friend in Washington for a change.”

Mayor Bloomberg countered that the harsh fiscal reality is that the city has to depend on itself because Washington “is just not going to bail out the states and it’s not going to bail out the cities.”

Asked to name other ways of reducing the budget, Thompson vowed to end no-bid consultant contracts at the Department of Education; to undertake a top-to-bottom review of every agency to root out waste; and to re-instate the commuter tax, which Bloomberg called “pie-in-the-sky” think ing.