Peter Mandelson: Adopt the Euro for the sake of British business

What passes for our national debate about the single currency is beginning to be about anything bar the actual economic implications of whether we go in or whether we stay out. Despite the clear evidence that the economics is coming right, the realistic possibility of a referendum may be ruled out for this Parliament.

Contrary to the way this subject is reported, I do not make speeches on behalf of Tony Blair. I do so because I believe passionately in what is in this country's interests. But when a Labour government committed by its own statements to British membership of the euro has been elected by massive majorities, and when to most objective eyes the progress towards convergence has been substantial, we cannot blame international business for cavilling at what looks like another Duke of York act of marching the troops up the hill and marching them down again.

Promises of another look "sometime in the future" or in the "next Parliament", I fear business will read "never" and act accordingly. It may be that it is possible to demonstrate that the Five Tests have not been passed in a "clear and unambiguous" way. But by ignoring the costs of staying out – lost trade, lost inward investment, lost productivity gains, instability caused by a volatile currency and a loss of influence over European economic reform – the achievement of this Labour government's central economic objectives is being endangered.

An adverse euro decision makes business less likely to choose to invest in Britain. It undermines the health of our long-term economic base and makes it more likely that at some point in future we will have to make hard choices as a government between tax increases and lower public spending.

My plea to the Cabinet is that they look at the position in the round, and over the long-term. Not to do so would truly be a dereliction of our duty to the people who elected us.

That's why I say the time has come for everyone, but for the Labour Party and trade unions in particular, which have taken a settled pro-European position for nearly two decades, to wake up to what is at stake for hard-working families in Britain. There is still time to get this decision right. I hope for all our sakes, the door is not slammed shut again.