Hammond forced to defend OBR forecasts as pro-Brexit Tories rage

The UK government has been forced to defend growth forecasts in Wednesday's Autumn Statement after leading pro-Brexit Conservative MPs attacked them as too pessimistic.

The independent Office for Budgetary Responsibility said the UK would have to borrow £122bn more than planned over the next five years and cut growth forecasts to 1.4% for next year.

Other economists pointed out that the cut in growth was actually above consensus forecasts.

However, former work and pensions secretary Iain Duncan Smith described the OBR forecast as "another utter doom and gloom scenario" by an organisation "that simply hasn't got anything right".

"The key thing is that the OBR has been wrong in every single forecast they've made so far. On the deficit, on growth, on jobs, they've pretty much been wrong on everything."

Fervent Eurosceptic and Conservative MP John Redwood was almost apoplectic with rage in parliament on Wednesday after Chancellor Philip Hammond delivered his statement.

"The OBR is probably still quite wrong about 2017 - their forecast is too low, their borrowing forecast is too high, and we will get good access to the single market once we are out of the EU."

However, Hammond defended the OBR, telling the BBC forecasting was "not a precise science".

"We should think of it as one of the possible range of outcomes we need to plan for."

Economist Paul Hollingsworth at Capital Economics pointed out that the OBR's economic forecasts were more upbeat than expected, with the GDP growth of 1.4% next year above the consensus forecast and growth throughout the rest of the forecast period expected to exceed both the consensus expectation and the Bank of England's more optimistic forecast.

He noted that the weaker growth forecasts is bad news for debt and borrowing, and therefore limited the potential for fiscal boosts to the economy to £8bn per annum by 2019/20.

"Although the Chancellor’s package of measures gave a bit of money away, there is still set to be a fiscal tightening (proxied by the change in the cyclically-adjusted budget balance as a percentage of GDP) equivalent to just under 1% of GDP per year over the next three years. That said, his new fiscal rules still give him some room to scale back the pace of tightening if the economy were to take a bigger-than-expected hit over the next few years," said.