A separate "health tax" should be introduced to help the NHS catch up with other "more advanced" European countries, former health secretary Alex Neil has said.

He claimed the "deeply controversial" levy would help convince the public to back tax rises.

Mr Neil said an extra £10 billion a year would be needed across the UK by the end of this parliament to bring healthcare up to the level of Germany.

The tax is one of several recommendations set out by Mr Neil in a 10-point improvement plan to address challenges facing the NHS.

Launching the plan in Glasgow, Mr Neil said: "The whole British system is in stress and while efficiency savings are needed, they will not be enough, which is why I float the idea of a separate health tax - deeply controversial but cannot be ignored.

"We haven't caught up with more advanced European partners and I think at a UK level we have to try and do that, otherwise we are going to face a crisis right across the UK.

"It's already happened south of the border and it will get a lot worse everywhere if we don't put additional resources in.

"I've suggested a major tax change which I think should apply across the UK, not just in Scotland, and that is a dedicated health and social care tax which would probably be a combination of income tax and national insurance contributions so that people can see clearly how much money is being raised for health and social care and how much money is then being invested in health and social care."

Mr Neil said there would be consequential reductions in the rest of income tax and national insurance contributions.

The NHS already accounts for 40% of the Government's current budget - a proportion that cannot be significantly increased without impacting on other areas, Mr Neil said.

He said Scotland's share of £10 billion a year would be £800 million to £900 million and that it would be hard to estimate what this would equate to per head of the population.

Mr Neil said: "There's not a simple answer because we don't have capital gains tax in Scotland, we don't have corporation tax, we don't have national insurance contributions.

"The £800 million into a population of five million can give you the per-head money which is required."

Other recommendations include a "long-term, detailed strategy and business plan", covering the period to 2030, measures to prevent ill-health and improved earlier detection of diseases such as cancer.

Mr Neil also advocated increasing the supply of new doctors and nurses by a "substantial number" as well as "urgent measures to address staff shortages in the NHS and social care".

The plan was published by the Options for Scotland think-tank run by former SNP leader Gordon Wilson.

Labour health spokesman Anas Sarwar said: "This is a humiliating intervention for the SNP government.

"The mismanagement of the NHS by the SNP is now accepted by one of its own backbenchers and a former health secretary."

Scottish Liberal Democrat health spokesman Alex Cole-Hamilton said: "Healthy debate makes for better policies, so why were none of these more radical ideas floated earlier?

"The truth is it says a great deal about an SNP government obsessed with independence and which doesn't tolerate any rocking of the boat, criticism or alternate thinking within its own ranks."

Scottish Conservative health spokesman Donald Cameron said: "There's no question that the NHS in Scotland needs substantial review and many of these points are worthy of consideration.

"But as long as the SNP prioritises the break-up of Britain over the running of the NHS, no real improvements will take place."

A Scottish Government spokeswoman said: "We are investing record amounts in the health service and staff numbers are also at an all-time high.

"However, we want to do even more and through our health and social care delivery plan we are already taking forward many of the suggestions in this paper - including a heavy focus on preventative actions such as minimum unit pricing for alcohol and on tackling wider health and social inequalities.

"We will do everything required to ensure Scotland continues to have world-class healthcare and will consider all positive suggestions. However, we have no plans to introduce a hypothecated health tax."