The continuing political mess over Brexit is a “crushing disaster” for business in Britain with investor confidence at the lowest since the financial crash a decade ago, the Confederation of British Industry’s director general has said.

Carolyn Fairbairn told business leaders in London that “the paralysis” in Westminster continuing “every day without a deal is corrosive” in its effect on Britain’s economy.

She said the government and other political parties involved in the Brexit mess needed to sit up and pay attention to the realities in business and stop shirking their responsibilities to the country, where business leaders are already being forced to cancel expansion because the prospect of a decision on Brexit seems further away than ever.

“From the heart of business to the heart of politics, resolve this gridlock, do whatever it takes and do it fast,” she said.

Fairbairn added that if cross-party talks were to fail, as widely expected, Theresa May or her successor, should “move to the next stage, fast”.

At a speech at the Mansion House, Fairbairn said the CBI’s surveys show that intentions to invest were “at their lowest since the financial crash” a decade ago.

Stockpiling is at its highest level since the 1950s, businesses were sinking hundreds of millions into contingency plans with “no upside” while “politicians prevaricate”, she said.

Failure in Westminster would inevitably mean support for an election or second referendum would grow, pushing the final decision of Brexit further into the distance.

“Business needs pace, decisions, leadership … measured in days and weeks, not months and years,” she told the gathering of leaders, which was also being addressed by the business secretary, Greg Clark.

She singled out the creative and tech firms moving their headquarters to Europe, compromising the UK’s hopes of building on its current successes in the sector.

International satellite broadcasters, which have long been based out of London, are being forced to move elsewhere in the event of no deal while financial services including insurance firms and bankers have already decamped part of their operations to France, Germany, the Netherlands, Luxembourg and Ireland.

France and the Netherlands are aggressively pursuing Brexit spoils, with the Dutch government revealing earlier this year it was hoping to lure 250 businesses.

Discovery and Bloomberg have already announced their intention to invest in the Netherlands because of Brexit.

France has identified 50 companies, including motor and pharmaceutical industries, that it is trying to entice across the Channel while the European Medicines Agency has moved to Amsterdam with the loss of 900 jobs in the UK.