Mayor Bill de Blasio has signed off on pay hikes of at least 12 percent for the city’s elected officials and approved a recommendation by an independent panel that the 51 City Council posts be full-time with outside employment limited, according to a letter released Thursday.

De Blasio says limiting council members’ outside pay would reduce the appearance of conflicts of interest.

“Such a proposal would require all council members to wholly dedicate themselves to their office and forego any non-city employment that could require a significant amount of their time,” de Blasio wrote to City Council Speaker Melissa Mark-Viverito.

“Accordingly, full-time status would preclude outside employment other than de minimis activities — such as writing an article or teaching as an adjunct professor,” he said.

With the mayor’s signature, the recommendations of the Quadrennial Advisory Commission will go before the City Council.

The three-person panel recommended that City Council members other than the speaker should receive a 23 percent pay increase to $138,315. In exchange, the bonuses they receive for chairing commissions — called lulus and averaging $8,000 per person — would be nixed.

The council speaker should make a total $154,375, the commission said. The post currently comes with a $112,500 base salary and a $25,000 lulu.

The panel said the mayor should be paid $258,750, based on factors including increases in the cost of living and salaries of comparable officials in other cities.

De Blasio, who makes $225,000 annually, said he will not accept a raise this term.

The city’s elected officials, including the public advocate, the city comptroller and the five borough presidents and district attorneys, have not received a raise since 2006.