The amendments, published today (7 October), will be debated in the House of Lords next week and if approved would enable the Welsh Assembly to set different Welsh rates of income tax for each tax band, subject to a referendum.
Stephen Crabb, Secretary of State for Wales, said:
The new income tax powers are a tool to help the Welsh economy become more dynamic and make Welsh Government more accountable.
Used correctly, they can boost economic growth meaning more people in Wales in jobs enjoying a better standard of living.
But I have always believed these tax powers need to be flexible, which is why we are now removing the lockstep restriction on how the powers are used. This is devolution with a purpose.