LONDON, Nov 9 (Reuters) - Britain could take five to 10 years to properly recover from the pandemic because the COVID-19 financial hit will sap the economy of the firepower it needs to rebuild for Brexit, advertising supremo Martin Sorrell said on Monday.

Britain has recorded the worst death toll in Europe and the deepest economic contraction of any leading G7 nation from the coronavirus, forcing it to pump more than 200 billion pounds ($263 billion) into the economy to keep it afloat.

It is now preparing to finally leave the European Union on December 31, and is yet to secure a future trade deal.

"It is going to take a long time for the UK to recover unfortunately," Sorrell, the founder of the world's biggest advertising company WPP and one of the longest serving chief executives of British listed companies, told Reuters.

"It's going to be a tough 5 to 10 years, we're going to be 5 to 10 years before the economy fully recovers from the Brexit withdrawal and the industrial changes that will need to take place, to re-skill, to re-educate, to invest in the necessary infrastructure." ($1 = 0.7610 pounds) (Reporting by Kate Holton; editing by Guy Faulconbridge)