Gordon Brown has convened an economic war cabinet to bolster Britain against the increasingly turbulent conditions in world markets and appointed Paul Myners, chairman of Land Securities and Guardian Media Group, as City minister.

"Quite simply, the new era that we have entered requires new ways of governing," Brown explained of the creation of the National Economic Council (NEC). "We don't just need to change policies to deal with the new financial difficulties but the way we take decisions, the way we govern, has got to change as well."

The creation of the council is one of several changes wrought by Brown in order to deal with the fall-out from the past three weeks which have seen the world's credit markets seize up, investment banks collapse, the effective nationalisation of Bradford & Bingley and the government forced to guarantee personal savings deposits of up to £50,000 amid fears that even more high street banks could fail.

The NEC was immediately branded by the City as an economic war cabinet.

"Call it what you will," Brown responded. "The important thing to say is that we are taking all the action that is necessary and we will do whatever it takes to ensure not just the stability of the economy … but also that we get the economy onto a path of growth, where people can see we are being fair in the way we deliver prosperity for the future."

"These are new times. The global economy will never be the same again. Huge changes are taking place. We have to deal with it in a new way."

Myners, who will be given a peerage in order to take up his post, will resign from his commercial posts - and even his post as chair of the trustees of the Tate gallery - and sell any shares he owns.

He is not taking a salary from his new ministerial post and City sources estimate that he is giving up at least £1m a year by resigning from his various corporate jobs. He is also losing more than £3m worth of shares in hedge fund GLG, where he is currently a director, a post he will also quit.

"There is a serious job to be done," Myners said. "And I look forward to working with the Chancellor but I have nothing else to say at this stage as my focus is getting to grips with my new job."

He is allowed to retain his charity positions so he will remain a trustee of Glyndebourne and the Smith Institute, an independent think tank which looks at equality and enterprise. He will, however, hve to resign his chairmanship of the Low Pay Commission.

The former Marks & Spencer chairman will join the rest of the NEC at its first meeting on Monday morning after which Alistair Darling will make a statement to the House of Commons about the economic crisis.

Also round the table will be the chancellor, the foreign secretary, David Miliband, new business secretary, Peter Mandelson and eight other Cabinet ministers, as well as new science minister Lord Drayson, and another new face, Stephen Carter.

The former chief executive of Ofcom, who left the regulator to work at City PR firm Brunswick before joining Brown as his strategy chief, has been made junior minister for communications, technology and broadcasting. He will also receive a peerage.

The NEC will coordinate "efforts to help families deal with higher food and energy prices", according to a statement, and "provide the forum on how to equip the country for the future by making the right investments in education, skills, science and infrastructure".

The Council will also have responsibilities to promote the development of sustainable and secure energy supplies; to tackle barriers to entrepreneurship and small business growth; and to address the UK's housing and planning needs.

Brown has also drafted in a legion of City grandees to act as business ambassadors who will promote UK trade overseas. The ambassadors are Barclays chairman Marcus Agius, Lloyds TSB chairman Sir Victor Blank, Vodafone's chairman and former HSBC boss Sir John Bond, former BP boss Lord John Browne, Sir Terence Conran, chairman of Standard Chartered bank Mervyn Davies, chairman of the London Stock Exchange Chris Gibson-Smith, UCL provost Malcolm Grant, Sainsbury's chairman Sir Philip Hampton, Oxford University vice-chancellor Dr John Hood, Lord Digby Jones, Anna Mann from MWM Consulting, BAE Systems chairman Dick Olver, Cambridge University vice-chancellor Professor Alison Richard, architect Lord Richard Rogers, chairman of Rio Tinto Paul Skinner and chief executive of GKN Sir Kevin Smith.