First Minister Carwyn Jones is to hold talks with Chancellor George Osborne to set out the case for reforming Wales’ financial settlement.
The Welsh Government is calling for a new and fairer system to fund Wales in the future, which would include the ability to borrow money to invest in infrastructure projects.
Devolving control of areas such as stamp duty and air passenger duty could also form part of a comprehensive package of reforms.
Ahead of the meeting in London on Wednesday, the First Minister said: “We know that the current way that Wales is financed – the Barnett Formula – is long out of date. Over time, it is very likely to lead to ever-greater underfunding of Welsh public services.
“Clearly, that is unacceptable, and any new system must address that problem.
“We also need to correct the anomaly that Wales will be the only part of the UK where the Government cannot borrow to fund investments in projects such as roads and hospitals.
“We are open-minded about the scope for reform in other areas, including the possibility of devolving some powers over taxes. Substantive talks need to get underway soon. We will consider any package of proposals that offers the people of Wales a fair and sustainable financial settlement.
“This is not a separatist agenda, it is about developing a financial system that supports our maturing devolution settlement and strengthens Wales’ place within the UK.
“I look forward to the Chancellor setting out the UK Government’s thinking on how we take this agenda forward.”