Andy Hayman, a former Metropolitan Police assistant commissioner who was in charge of the UK's counter-terrorism policy and operations until last year, said changing the rules again would simply create "confusion".
The restrictions were introduced in 2006 after the discovery of a plot to blow up planes using liquid bombs disguised as soft drinks, a plan which could have caused more carnage than the September 11 attacks.
Islamic extremists Abdulla Ahmed Ali, Assad Sarwar and Tanvir Hussain were found guilty of conspiracy to murder by detonating the bombs on airliners yesterday following the largest ever counter-terrorism operation in the UK.
As the men face life sentences, it today emerged that new scanners are being trialled at Newcastle Airport which could identify potential explosives disguised as everyday liquids.
Mr Hayman said: "My view is that following the disruption that we had in 2006 the public has got drilled into what's expected in view of passenger safety.
"We are aware of this new technology that's been developed in the last two or three years.
"It's my view that to try and go back to what we had just adds to the confusion.
"What we'd like is to have the technology in place as well as the restrictions, then people know what's expected."
Mr Hayman described yesterday's convictions as "a very good result" but added that it was "bittersweet".
"These people have now been found guilty but now the public is aware of the lengths that people will go to, which is very scary," he said.
The jury failed to reach verdicts on charges relating to four other defendants but Mr Hayman said he did not believe that a second retrial would be "wise".
"To go into another retrial, I don't think it would be a wise thing to do. We have got the main ringleader."
The police investigation which led to the trial cost more than £35 million and the two trials ran up an estimated bill for a further £100 million.
Mr Hayman said the price was worth paying if lives were saved as a consequence.
"I remember facing all the survivors and bereaved families of the victims of 7/7 and seeing the pain etched on their faces," he said.
"I don't know how I could stand in front of future victims and say I don't think it was worth the money.
"I don't think there's a price we can put to this."
Gordon Brown paid tribute today to all those involved in the counter-terrorism operation leading to yesterday's convictions.
His spokesman told a daily briefing of journalists in Westminster: "The Prime Minister wishes to express publicly his gratitude to the police, security and intelligence agencies and all those involved in the work they did.
"Their professionalism and dedication prevented lives being lost in this country to terrorism."
The British-born terrorists, controlled and funded by al Qaida masterminds in Pakistan, planned to detonate home-made liquid bombs, concealed within 500ml Oasis or Lucozade bottles, on flights bound for major North American cities.
Ali, 28, of Walthamstow, east London, was inspired by the July 7 bombers and Osama bin Laden and considered taking his baby son on his suicide mission.
Police said the plot was drawn up in Pakistan with detailed instructions passed to Ali during frequent trips to its lawless border with Afghanistan.
Surveillance teams watched as the unemployed former shop worker used cash to purchase a £138,000 second-floor flat in Forest Road, Walthamstow, east London.
They planted a secret bug which revealed the property had been converted into a bomb factory.
The flat was also used as a location for Ali and others to record suicide videos threatening further attacks against the West.
In his video, Ali warned the British public to expect "floods of martyr operations" which would leave body parts scattered in the streets.
Along with Ali, Sarwar 29, of Walton Drive, High Wycombe, Buckinghamshire, and Hussain, 28, of Nottingham Road, Leyton, east London, will be sentenced for the airliner plot on Monday.
The trio were convicted of conspiracy to murder in the first trial last year but retried, along with five other men, for the airliner plot after the first jury failed to reach verdicts on those charges.
The jury failed to reach a verdict on Umar Islam, 31, of Bushey Road, Plaistow, east London, in connection with the airliner plot.
But Islam was convicted of conspiracy to murder and will also be sentenced next week.
Adina Ezekiel, for the prosecution, said a decision would be announced on Monday about whether they would seek a re-trial of four other men.
The arrest of the gang in August 2006 sparked tight restrictions on carrying liquids on to aircraft which initially caused travel chaos.
Current rules state that travellers can only carry 100ml containers on to an aircraft and the bottles or tubs must fit into a re-sealable bag measuring 20cm by 20cm.
Major airlines and the British Airports Authority have since called for the rules to be eased or reviewed.
A spokeswoman for Virgin Airlines said: "With better technology coming on stream, it is appropriate to review the restrictions to ensure passengers are able to make as easy a journey as possible through airport security checks."
The new hi-tech scanner, developed by Sedgefield-based firm Kromek, uses an X-ray beam to distinguish between harmless liquids, such as water or alcohol, and potential explosives such as hydrogen peroxide.
Kromek's Dr Arnab Basu told Sky News: "If you are trying to carry a liquid which looks and weighs very similar, but is very different in nature, this machine will recognise it very reliably."
A British Airways spokesman said: "We have always supported rigorous security screening on the ground.
"Any new security procedures that lead to a smoother journey for our passengers while improving aviation safety is welcome.
"We would like to see security procedures harmonised internationally to avoid confusion and make compliance easier. It would be unhelpful to maintain a liquid ban at some airports and not at others."
A Department for Transport spokesman said: "Trials of liquid scanning machines are now taking place in various European locations and the UK has significant involvement in the technical aspects of this work.
"The timing of any easing in the current restrictions will depend on the results of these trials, but in the meantime the present restrictions must remain in place in order to address the real and serious threat from liquid explosives.
"Protecting the travelling public is our highest priority and we will not do anything that puts passengers at risk."
David Learmount, operations and safety editor of Flight International magazine, said: "My view is that introducing this could take some time and even then it will be run alongside the current plastic-bags regime. This will mean that it may be a while before life gets any easier for airline passengers.
"I am sure airports and airlines would be only too happy to see equipment introduced that would speed people through airports.
"However, airport security is a matter for Government departments and it seems that either lethargy or a distrust of the system is preventing new equipment being brought in."
Mr Learmount said he had seen the scanners in use and it could even "tell the difference between Pepsi and Coca-Cola".
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