Former legal-aid barrister Lord Bach is to replace Emily Thornberry as shadow attorney general as part of a mini-reshuffle among Labour ranks.
Ms Thornberry left her post last month over a tweet that was branded "snobby".
She apologised for the message, which showed a terraced house with three England flags and a white van outside.
Other Labour MPs on the move include shadow welfare reform minister Chris Bryant, who takes the shadow minister for the arts post.
Hull East MP Karl Turner becomes shadow solicitor general, while retaining his role as an opposition whip. Shadow arts minister Helen Goodman takes on the shadow welfare reform brief.
The appointment of Lord Bach of Lutterworth shifts the focus of the shadow attorney general role from the House of Commons to the House of Lords.
Raised to the peerage in 1998, Lord "Willie" Bach will retain his role as a Foreign Office spokesman in the Lords.
A former government whip, who describes himself on Twitter as "still fighting the good fight against legal aid cuts", Lord Bach has served as a junior minister in the Lord Chancellor's Department, the Ministry of Defence, the Ministry of Justice and the Department for Environment, Food and Rural Affairs.
Ms Thornberry was shadow attorney general for three years until she stepped down in November over her tweet while voting took place in the Rochester and Strood by-election in Kent. Alongside the picture, Ms Thornberry wrote: "Image from Rochester."
Labour came third in the high-profile poll behind UKIP, which won the seat and saw its second MP elected to Westminster.
Ms Thornberry said later she had "made a mistake" and apologised "if she had upset or insulted anybody".