The chief executive of British Airways owner IAG has hit out at the Government’s lack of Brexit progress, branding it “shocking” that the country still has no clarity on the future.

Willie Walsh also said in the company’s annual report that all the “credible forecasts” show that Brexit will have a negative economic impact, adding that IAG must remain “very agile” to navigate the immediate risks.

He said: “I think it is inevitable that Brexit will have a greater impact in the months ahead. It has been quite shocking to get so far in the political process without having any real clarity about the future. That can’t be positive for the economy.

“Whether you are for or against the UK leaving the EU, all the credible forecasts I’ve seen predict that Brexit will have a negative economic impact in the short to medium term.

“That is likely to damage consumer confidence and act as a further drag on business investment. We need to remain very agile in the months ahead.”

The comments come as Theresa May has still not put her roundly criticised Withdrawal Agreement to Parliament, with just weeks to go until Britain quits the EU.

The Prime Minister has been under intense pressure from the Eurosceptic wing of her party to ditch the so-called Northern Irish backstop, which she insisted upon in negotiations with the EU.

Mr Walsh also described Brexit as the “biggest unknown” in 2019, but vowed not to be distracted by the uncertainty it was bringing.

Last month IAG, which also owns Aer Lingus and Vueling, placed a limit on non-EU shareholders.

EU regulations stipulate that airlines must be more than 50% controlled by investors from the bloc to fly freely across the continent.

But IAG insisted at the time that the move wasn’t linked to Brexit and that UK residents would be treated in the same way as those from the EU, even after Brexit.

Mr Walsh has also recently said that he is confident there will be a comprehensive air transport agreement between the EU and the UK.

“We refuse to be distracted by the uncertainty and are very focused on continuing IAG’s recent record of success,” IAG added on Tuesday.