Companies that may be the subject of large antitrust investigations, like Google, will pose a challenge for U.K. regulators after Brexit | Josh Edelson/AFP via Getty Images Brexit Files Insight Antitrust angst for the UK The EU used to deal with big competition cases on Britain’s behalf. That’ll change after Brexit.

In recent months the U.K.'s competition agency has opened probes into, among other things, an alleged cartel between decorating companies and a merger between online takeaway firms.

Important cases no doubt, with potentially millions of pounds at stake and extra protection for consumers. But these investigations are small beer compared with what the agency will have to take on once the U.K. leaves the European Union.

Currently, the mega antitrust cases — grappling with global behemoths like Google and GE — are handled on Britain's behalf by the European Commission. After Brexit, the job of policing these and global mergers worth tens of billions of pounds will fall to the U.K.'s Competition and Markets Authority (CMA). Will it be up to the job?

Step up Andrea Coscelli, an Italian economist who was this week appointed CEO of the CMA. Coscelli has a tough job ahead of him and the costs of separation will be palpable. Under a hard Brexit, instead of pooling their fire-power, British and EU investigators will conduct parallel inquiries, meaning extra costs for taxpayers and extra red tape for business.

The agency will certainly need more cash. Coscelli predicts investigations into as many as 50 extra mergers per year — a 50 percent rise.

And the Commission at present handles the more resource-intensive ones. Its nine-month review of Dow and DuPont's $130 billion tie-up analyzed data on thousands of insecticides, herbicides, pesticides, fungicides and nematicides, with a large team working round the clock.

The same is true for antitrust and cartel investigations. Post Brexit, U.K. officials will need to grapple solo with the Googles, Qualcomms and MasterCards of tomorrow. As part of the Commission's high-profile inquiry into how Google uses its search results to favor its own Google Shopping service over rivals, the Commission assessed 5.2 terabytes of data — equivalent to 1.7 billion search queries.

The case resulted in a €2.4 billion fine, and yet the probes into Google are far from over.

Without new resources, attention will inevitably migrate from the important regional work that keeps the economy ticking to the big cases involving multinational companies. And even if the CMA receives more resources, will it still be able to attract the best talent from across Europe like its new Italian CEO?

Price fixers and greedy monopolists will be hoping not.

This insight is from POLITICO's Brexit Files newsletter, a daily afternoon digest of the best coverage and analysis of Britain’s decision to leave the EU. Read today’s edition or subscribe here.