U.S. Labour Secretary Hilda Solis is telling colleagues she is leaving the Obama administration.

In an email message, Solis says she submitted her resignation letter to President Barack Obama on Wednesday afternoon. She says she made the decision to leave after discussing it with her family and close friends.

Solis has won praise from labour unions for aggressive enforcement of wage and hour laws and job safety regulations. But business groups have criticized her as not taking a more co-operative approach.

Meanwhile, a White House official says Attorney General Eric Holder and the secretaries of Health and Human Services and Veterans Affairs will remain with the Obama administration as it enters a second term.

The official said Holder, who leads the Justice Department, and HHS Secretary Kathleen Sebelius and VA Secretary Eric Shinseki will remain with the administration amid changes to the Cabinet. 

The three remaining officials were not an exhaustive list of which Cabinet members intended to stay, said the official, who spoke on condition of anonymity.