Sir Keir Starmer's "relations reset" with the European Union looks set to come under scrutiny in an inquiry launched by the Foreign Affairs Select Committee.
The inquiry, which is calling for evidence on cross-continent relations, comes amid growing concerns about Donald Trump's stance on Europe and the "risk" posed by China.
Starmer will need to address how the UK can maintain "strong relations" with the US and EU and if divergence from the EU risks Britain's trade relations with Beijing.
The Foreign Affairs Select Committee, which is led by ardent Remainer Emily Thornberry, claimed Brexit left the UK with "no formal mechanism to engage and coordinate action on pressing shared challenges".
Sir Keir Starmer delivering a statement at Downing StreetPAIt added: "Various limitations in the current economic relationship have also been identified that act as a barrier to trade in goods and services."
Experts will also be hauled in to give evidence on "what the long-term strategic objectives are in the reset and what frameworks and agreements might be needed to support a strategic partnership between the UK and EU".
The Foreign Affairs Select Committee is requesting for submitted written evidence to not exceed 3,000 words.
The deadline to submit written evidence is April 8.
LATEST DEVELOPMENTS:
President of the European Commission Ursula von der Leyen gives a speech at the European People's Party (EPP) annual congress GettyStarmer, who is committed to the UK remaining outside both Brussels' single market and customs union, reiterated his goal of resetting cross-Channel relations after entering No10.
The Prime Minister is also now playing a leading role in directing Europe's response to Ukraine, having hosted a Lancaster House summit last weekend that included French President Emmanuel Macron and Ukrainian leader Volodymyr Zelensky.
In evidence given to the House of Lords European Affairs Committee in December, EU Relations Minister Nick Thomas-Symonds set out three pillars for the Prime Minister's reset.
He said: "The first pillar is security and is about co-operation, particularly on foreign policy but obviously on wider defence matters too.
Following the disastrous Zelensky-Trump bust-up in the White House, America paused military aid and intelligence sharing with UkraineREUTERS"The second pillar I would describe as the safety of citizens. That is closer law enforcement co-operation in a number of areas of serious and organised crime on things such as counter-terror operations, tackling money laundering, and irregular migration.
"The third pillar is growth and trade. You will have seen from our party election manifesto that this involves, for example, seeking to negotiate a sanitary and phytosanitary agreement with the EU, pushing forward on mutual recognition of professional qualifications in services, and what we can do to make it easier for our touring artists to perform in the EU."
However, there have been reports that Starmer's Government could controversially buckle to Europe on a youth mobility scheme.
Other concessions Brussels remain hopeful to extract from Britain revolve around fishing rights and the jurisdiction of the European Court of Justice.
