The Scottish National Party (SNP) wants a majority in the devolved parliament to demand another referendum, although British Prime Minister Boris Johnson reiterated that he will not grant one.
Sterling ticked up during the session against both the euro and the dollar. At 1510 GMT it was up 0.17% at $1.3909 and rose 0.25% against the euro at 0.8629 pence.
"Policy metrics will remain on hold with the need for on-going support maintained," said Stuart Cole, head macro economist at Equiti Capital.
The SNP has pledged to call for a second Scottish independence referendum, although permission to do so will need to be granted by the UK government in London.
Sterling was 0.3% lower against the dollar at $1.3875. It was 0.1% lower to the euro at 86.99 pence.
"A bearish-dollar outcome of the Fed meeting today should provide an extra tailwind for cable to make another attempt at the $1.40 level later this week."
Sterling was 0.15% higher on Monday at $1.3901 , off last week's top of $1.4009. Against the euro it was 0.2% higher at 86.92 pence.
Bank of England Deputy Governor Ben Broadbent has forecast consecutive quarters of rapid growth but also warned that inflation will prove less predictable
Sales volumes leapt by 5.4% in March from February, the Office for National Statistics said. Economists polled by Reuters had expected an increase of 1.5%.
On top of retail sales, a survey showed a deluge of orders swept through British businesses in April as the country lifted some of its restrictions, pointing to a rapid rebound for the pandemic-hit economy.
The pound on Tuesday hit a six-week low against the euro and extended losses against the dollar after the announcement of Andrew Haldane's resignation.
It was 0.1% higher to the euro at 86.77 pence, off a six-week low of 87.11 pence after the Haldane announcement.
While the reaction in currency markets was muted, with the pound holding close to the day's lows against its main rivals, Haldane's exit is widely seen as a departure of one of the more hawkish figures at the central bank.
Against the dollar, the British currency was down 0.1% at $1.3692, having touched its lowest since Feb. 5 at $1.3670 in the previous session.
The pound had its best quarter against the euro since 2015 in the first three months of 2021, boosted by the UK's vaccine rollout, which is one of the fastest in the world, as well as a fading of negative interest rate expectations.
Versus the dollar, the pound was down 0.1% at $1.3723, and also on track for a weekly loss.
The pound fell 1.2% against the dollar and 1.7% against the euro between Tuesday and Wednesday as investors took cash off the table after a strong first quarter for the British currency.
Sterling's pullback was "exaggerated," ING analysts wrote, adding that they were "constructive" on the pound, citing Britain's relatively fast COVID-19 vaccine programme.
The pound fell on Tuesday, losing 0.6% against the dollar and over 1% against the euro - its worst day against the single currency in five weeks as investors took cash off the table.
Against the euro, it traded 0.7% lower to the euro at 86.50 pence, having hit a five-week low of 86.62 pence.