The eurozone economies are a "ticking time bomb" that will damage the UK if it stays in the EU, a Birmingham Labour MP and chairwoman of the Vote Leave campaign has warned.
Gisela Stuart, who has represented Birmingham Edgbaston since 1997, pointed to calculations by the pro-Brexit group that suggested rapidly rising pension and debt liabilities would require taxes to rise by at least 17.6 per cent across the single currency group.
"This daunting demographic reality just goes to show that the eurozone is a ticking time bomb - an alarming reality that all EU members will inevitably be affected by," she said.
"The priorities of the eurozone will gradually and inevitably take over Brussels institutions. If we don’t want to be part of this, we must vote 'leave'."
The German-born Labour MP has been a firm eurosceptic since being part of the UK delegation to the European Convention that was tasked with drawing up a constitution for the EU.
She said that experience showed there was "a mule-like refusal to listen to democratic concerns or accept any suggestions of deviation from the orthodoxy of political integration".
"Questions like democratic accountability and economic competitiveness, which are so central for us in Britain, are downgraded in case they become a diversion from the European project," she added.
"I call it integration at whatever the cost or consequences."
Ms Stuart compared the EU to a failing bank or utility company and encourage voters to "switch" supplier.
"For years, British governments have tried to be pragmatic about Europe. They have taken the view that you can always kick the big decisions down the road," she said.
"That we can be inside the EU without being part of the ‘state building project’. But to be in both camps became impossible when the euro was created.
"Now the time has come to decide what is in the best long-term interest of this country.
"If the EU were an energy supplier or a bank, you would long ago have stopped believing its marketing, you would have seen it was hopeless value for money and never listened to its customers.
"You would just move your account. It is time for Britain to recognise that Brussels has had enough chances. And that the only safe option is to Vote Leave."
Vote Leave said projections of dramatic rises in the proportion of older people in the eurozone populations "raise significant questions about the long-term economic competitiveness of eurozone countries".
Combined with an excessively optimistic European Commission expectation that there would be no increase in public debts over the next 10 years, it said, that was a recipe for disaster.
The cost of public pension expenditure was estimated to rise by 2.1 per cent of GDP between 2015 and 2050, from 12.1 per cent to 14.2 per cent and the cost of debt interest payments from 1.8 per cent of GDP to 6.9 per cent of GDP over the next 35 years, it said.
Plugging the gap could mean raising the total revenue collected from taxes by 17.6 per cent, it suggested.