Mayor Bloomberg yesterday took a thinly veiled swipe at surging mayoral candidate Bill de Blasio for flip-flopping in de Blasio’s call for tax hikes on the rich.

De Blasio has made raising the income-tax rate for those earning $500,000 or more a central part of his platform despite having opposed higher taxes on Wall Street bonuses in 2010.

“Some of the candidates today that are yelling and screaming, ‘I’m going to raise taxes, I’m going to tax the rich’ — go back a year ago and you’ll find they were opposed to doing all that when they weren’t in the middle of running for office,” Bloomberg said.

But de Blasio noted Bloomberg signed a temporary income-tax hike, to 4.45 percent, on those earning $500,000 or more amid the economic slump after 9/11.

De Blasio’s proposal — which he said is different from the bonus tax — would temporarily hike the tax rate to 4.3 percent for those in that income group.