BOE policymakers revised their forecast for quarterly economic growth in the final three months of the year to 0.2 percent from 0.3 percent. They added the outlook for the first quarter of 2019 was likely to be similar.
"Brexit uncertainties have intensified considerably since the committee's last meeting," MPC members said in a summary of the December meeting.
"These uncertainties are weighing on financial markets."
The BOE also repeated its view that benchmark rates could move in either direction post-Brexit, depending on how it unfolds.
With 99 days to go until Britain is due to leave the EU on March 29, deep divisions in parliament have raised the chances of the world's fifth-largest economy abruptly leaving the bloc without a deal.
The heightened risk of a disorderly Brexit has also increased calls for a second referendum to break the deadlock.
Earlier this month, embattled Prime Minister Theresa May pulled a vote on her Brexit deal after admitting lawmakers would most likely vote against it.
May is now seeking "assurances" from EU leaders over the nature of the so-called Irish backstop post-Brexit.
The backstop plan is essentially a legally-binding insurance policy to ensure there is no hard border between Northern Ireland and the Republic of Ireland whatever the outcome of future trade talks between the U.K. and the EU.
Critics of the current deal say Britain could end up being trapping the country in a customs union with the EU indefinitely.
However, May has repeatedly insisted if her deal is rejected then the U.K. could be forced to leave with no-deal — an option big business leaders dread — or the whole Brexit process could be reversed altogether.
The prime minister has rescheduled a vote on her Brexit deal for the third week of January.