The senior economist at Aviva Investors said a further box had been “ticked” during the Brexit debate but there were “several hurdles” to come.
The EU bill debate has led to confirmation that there will be a vote on the Article 50 deal and a potential agreement forming the new relationship between the UK and the bloc.
Speaking on Bloomberg, Mr Robertson said the wheels were in motion but the pound sterling could get weaker as the process continues.
“I think we’re a little bit closer. It’s another box ticked on the progress towards triggering Article 50. The schedule is still on track for being triggered by the end of March, so it’s another little hurdle passed. There’ll be several more.
Stewart Robertson said sterling may weaken further
It’s another box ticked on the progress towards triggering Article 50
“But even once it’s triggered really then the real stuff happens when you actually have to have the negotiations, you have to have the detail and that’s a planned two year period, could be longer than that, the proof is in that pudding really.
“The reaction you’ve had in sterling, which is really a Brexit effect, is understandable in a world that is so uncertain and completely changed from what we’ve had for the last 40 years, it’s understandable that sterling has decided it needs a new level.
“Political uncertainty is something that currency markets hate and if we get some fraught tone to some of the negotiations, and it would be remarkable if it was as smooth as some have said, then often it’s currencies that react most.
- FTSE 250 hits RECORD HIGH as investors seek safety from Europe
- Ireland launches post-Brexit business grab attempt
“So although most valuation criteria will tell you that sterling is cheap, if you get those sort of difficulties in negotiations, sterling could fall further.”
Sterling made losses against the United States dollar this week as Parliament started voting on amendments to the Article 50 bill.
The pound to dollar exchange rate reached highs of 1.249 on February 6, but on Tuesday it dropped to lows of 1.235.
A weaker pound can make some products in the UK more expensive and reduces British peoples spending power while abroad. In contrast it can boost industries that export to other countries.
Get Quotes on Home Insurance
The Government comfortably saw off four opposition attempts to change the bill on Monday.
Theresa May's Brexit plan Mon, January 16, 2017
It's finally here!
Getty Images 1 of 7
Continued cooperation with the EU to tackle terrorism and international crime.
But Shadow Brexit Secretary Keir Starmer said while Tuesday's progress "wasn’t everything" Labour had wanted, it had secured a victory.
Sir Kier said: “The Government conceded that there will be a vote, not only on the Article 50 deal – which is the divorce settlement if you like – but also on the new agreement, which will be the new relationship between the UK and the EU at some time beyond 2019."
- PMQs LIVE: Theresa May and Jeremy Corbyn go head-to-head
- Guy Verhofstadt admits crumbling EU bloc could disintegrate
- Wales REJECTS Plaid Cymru bid to hijack Brexit labelled ‘DISGRACEFUL’