Bank of England chief economist says rates could stay lower for longer

The Bank of England may need to keep interest rates lower for longer than previously thought to reduce the chance of the economy slipping into long-term stagnation, its chief economist Andrew Haldane said on Friday.

Haldane said he was now more downbeat about the outlook for Britain's economy, due to weaker global growth, greater financial and political risks and the danger that wages and productivity might continue to fail to recover as forecast.

Read MoreBank of England chief sounds dovish note on rates

"Put in rather plainer English, I am gloomier," Haldane said. "This implies interest rates could remain lower for longer, certainly than I had expected three months ago."

The Bank of England
Alice Tidey | CNBC
The Bank of England

Haldane's remarks come at the end of a week in which markets have pushed back their expectations for the timing of the first BoE rate rise to towards the end of next year against a backdrop of hefty share price falls globally. Last month markets had expected the BoE would raise rates early next year.

In remarks to be delivered to local business leaders in Kenilworth, central England, Haldane said Britain's economy was "writhing in both agony and ecstasy".

While growth looked set to be the fastest of any major economy this year, and inflation and borrowing costs were low, real wages and productivity growth had endured the weakest run since the 19th century, apart from the aftermath of World War Two.

Read MoreBank of England holds fire as wage growth lags

Although it was possible that wages and productivity would start to pick up as the recovery continued, past BoE forecasts of this had proven wrong and financial markets were increasingly pricing in the danger that growth would falter.

He said that, rather than developing into a normal expansion, Britain could be at risk of "secular stagnation", meaning a long period of negligible growth.

"If there is genuine uncertainty about the path of the economy, the optimal policy response may be to avoid the worst outcomes," Haldane said.