In an interview with Sky News, Lord Falconer, Labour's Shadow Attorney General, has warned of a risk of the UK endangering its relations with the US under a possible Joe Biden presidency.
"What on earth is the point of making the United Kingdom an international pariah, just at the moment a [potential] new president of the United States emerges saying, not only do I want the British government to comply with the [Brexit-related] Northern Ireland protocol, but I want a law-abiding world?"
He went further by claiming that "to make ourselves an international outsider, somebody who will become low down the list of the people who the United States will want to do business with, is a very big mistake for the United Kingdom".
The Shadow Attorney General also argued that the UK government is "in a big hole" over the so-called Internal Market Bill that the House of Lords is due to amend later this week.
The bill is designed to give Westminster more power over devolved areas, including Northern Ireland in the EU's Customs Union in order to prevent a hard border on the island of Ireland.
The cabinet earlier admitted that the legislation may contradict the Brexit Withdrawal Agreement, resulting in heated debates within the governing Conservative Party, and harsh criticism from the opposition, as well as the EU.
Lord Falconer said that the government going ahead with the bill-related plans would mean that Biden was "not going to entertain negotiations" over a rapid post-Brexit US-UK trade deal.
The Shadow Attorney General was echoed by former Labour Prime Minister Gordon Brown who told the BBC last week that Biden may prefer to see the UK staying in the EU.
"He is also worried about the Good Friday agreement – he is not going to allow a trade deal with Britain to happen if we in some way breach the Good Friday agreement", Brown asserted, referring to a peace deal signed in 1998 between the British and Irish governments, and most of the political parties in Northern Ireland, on how Northern Ireland should be governed.
Ex-UK Envoy Warns Britain Will Face Repercussions if Biden Becomes US President
The ex-Labour PM's remarks come a few weeks after Peter Ricketts, the former British Ambassador to Paris and NATO, predicted in an interview with Politico that should Biden win the election, the UK government would face the challenge of building relations with Biden's team, who views Brexit as a risk to both European and British stability.
Ricketts argued that London should prepare for a Biden administration that keeps a particularly close eye on how Brexit affects Ireland, given the Irish influence in the Democratic Party and Biden's own Irish background. A Biden administration will prioritise trade with the EU just as the UK "has put itself out of an influential position in Europe", Ricketts claimed.
He spoke after Biden tweeted in September that "the Good Friday Agreement that brought peace to Northern Ireland" cannot become "a casualty of Brexit".
Biden has, meanwhile, proclaimed himself US president-elect even though the official tally of the 3 November election has yet to be released. Incumbent President Donald Trump, in turn, insisted that the election race is "far from over" and launched a legal battle against what he described as "fraudulent votes".