The UK has had a volatile, confusing time since voting to depart the European Union in 2016. According to some estimates, the economy is 3% smaller than it would have been if the vote went the other way. And even though the political and legislative process has been consumed by nothing but Brexit since the referendum, nobody knows what will happen next.

Enter the consultants. The National Audit Office recently revealed (pdf) that the government has spent “at least” £97 million ($124 million) hiring external help for Brexit-related tasks, because many departments lack necessary manpower and skills. The bulk of it went to six firms:

The government has defended the spending, telling the BBC that it was “often more cost-efficient to draw upon the advice of external specialists for short-term projects requiring specialist skills.”

The consultancy work ranged from the Home Office hiring PwC to produce and deliver communications about EU nationals living in the UK looking to settle permanently in the country after Brexit, to getting Bain & Company to help The Border Delivery Group understand the impact of a no-deal Brexit on industry, to the Cabinet Office tapping Deloitte for the vaguely titled “resilience planning.”

Consulting costs will continue to climb, because Brexit has been delayed from its original deadline of March 29 to Oct. 31 (and possibly beyond). Government departments extended 17 consulting engagements beyond their original deadlines in April, the last month for which data is available.

To be sure, this is just one sort of cost related to Brexit. In 2017, UK finance minister Philip Hammond earmarked more than £3 billion for government departments to spend on Brexit-related issues over two years.