The European Scrutiny Committee at the UK parliament said that it is not clear whether the UK government would be able to implement the policies through UK legislation alone, or whether implementation would require a "bilateral agreement" with the EU.
The Committee's report noted that the UK government has given its support, in principle, to the package of policies set out in the EU digital single market (DSM) strategy, which was set out in May 2015, as well as its commitment to "play an active role in the development" the strategy so long as the UK is a member of the EU.
However, it asked the government to clarify how it would implement each of the policies from the strategy after noting that some are "inherently cross-border in nature … and necessitate reciprocal commitments from more than one country".
"We request that the government provide the Committee with a case-by-case assessment of the extent to which, post-exit, the policy objectives of each of the different digital single market proposals could be achieved solely through domestic legislation or would require some form of bilateral agreement with the EU," the Committee said.
"We accept the Government’s reluctance to provide information 'about the nature of future agreements with the EU or on potential changes to domestic law following our EU exit', but believe that it is appropriate for parliament to seek clarification of which digital economy issues can be tackled domestically and which will require a bilateral agreement," it said.
The Committee has requested a response from the government by 9 May. It flagged particular concerns about how EU proposals to address unjustified restrictions on where data is stored and processed might impact the UK post-Brexit.
"[Lord Prior of Brampton, parliamentary under secretary of state at the Department for Business, Energy and Industrial Strategy] states that the government considers the free flow of data as being 'fundamental to the functioning of the digital economy' and that it 'sees global data flows as being of high importance, hence the desire to tackle unjustified data localisation not just at the EU level, but also in data flows between the EU and third countries'," the report said.
"This assessment tallies with concerns expressed by industry stakeholders, including techUK, that, post-exit, the EU could use certain DSM initiatives, notably the initiative on non-personal data …, to require UK-based digital businesses to relocate part of their operations to the EU. We urge the government to seek to expedite the bringing forward and agreement of this legislative proposal before the UK leaves the EU, and to ensure that the final regime does not disadvantage businesses operating in third countries," it said.