Maria Eagle has been promoted to minister of state at the Government Equalities Office (GEO), a step up from her previous position as parliamentary under secretary of state.
She will replace David Hanson, who is moving to the role of minister of state at the Home Office.
Her twin sister Angela, who is openly gay, has been promoted to minister of state for pensions from her previous role of parliamentary under secretary at the treasury.
Michael Foster, the MP for Hastings and Rye, is to fill Maria’s previous role at the GEO.
A GEO spokesman said: “This is an important agenda for the government which requires extra resource particularly as the Equality Bill makes its way through Parliament.
“That’s why Michael Foster MP has been appointed as parliamentary secretary. He will work, on an unpaid basis, as part of the ministerial team, supporting Harriet Harman, the minister for women and equality and Maria Eagle, [the] minister for state.”