The pound lost ground against its main rivals on Tuesday (24 January), as investors feared the Supreme Court Article 50 ruling will do little to derail the Brexit process.

The pound initially gained ground against the dollar after the decision was announced, before retreating sharply as the judges confirmed the UK's devolved assemblies will not have a vote on Brexit.

However, having hit a high of $1.2533, the highest level in over a month, earlier in the day, sterling was down 0.73% by mid afternoon, at $1.2440. The UK currency was also 0.53% lower against the euro, fetching €1.1574.

Earlier in the day, Britain's top court dismissed the government's appeal over Article 50, meaning Theresa May will have to ask MPs to vote before she can begin the formal process of leaving the EU.

The judges' court ruled by a majority of eight to three that the prime minister does not have inherited prerogative powers to trigger Article 50 and start the Brexit process without consulting Parliament.

FXTM research analyst Lukman Otunuga warned that while the ruling provided some clarity on the steps needed for Brexit to happen, the pending ongoing debate within the Parliament and potential complications could create a new layer of uncertainty, which could hit the pound.

"Since the historical vote to leave the European Union back in June 2016, the sterling has been gripped by uncertainty which continues to haunt investor attraction," he said.

"The buying sentiment towards the pound has become frightening low with the engine behind the pound/dollar's resurgence mostly attributed to dollar's vulnerability."

Meanwhile Fawad Razaqzada, market analyst at Forex.com, suggested pound/dollar might have "carved out a bottom" for the time being, adding he did not expect sterling to suffer another sharp decline.

"Most the pound-negative news may already be baked in the price," he said.

"With incoming UK data generally pointing to higher inflation and growth rates, the impact of the Brexit vote has so far been positive if anything. Market participants may therefore find it difficult to justify initiating new sell positions on the currency at these already-depressed levels."

Elsewhere, the dollar staged a solid rebound, overcoming the previous day's jitters as it gained against its main rivals, less than 24 hours after Donald Trump officially decided to withdraw the US from the Trans-Pacific Partnership (TPP), in his first major move since he took office at the White House at the end of last week.

The greenback was broadly flat against the euro but gained 0.45% and 0.21% against the yen and the Swiss franc respectively, trading at ¥113.22 and CHF0.9986 respectively.

The US currency was also 0.17% against its Canadian counterpart, trading at CAD$1.3257 but was largely unchanged against the Australian dollar.