Now, although they are angry that a public meeting set for June 13, where they hoped to discuss their concerns with police, was cancelled with little notice, it seems that more officers are on the way. Kensington and Chelsea police have increased the 'special contingent' in the market to six, supplementing the regular safer neighbourhood team patrols. Also, extra patrols operate in the early morning, when dealers arrive to open up on Saturdays.
But many dealers feel they are still not being given the attention needed for an area bringing in a huge number of visitors on Saturdays, boosting the local and London-wide economy.
Costas Kleanthous, chairman of the Portobello Antiques Dealers' Association, said Portobello is one of the most popular tourist spots in the capital, attracting more than 60,000 visitors on summer Saturdays and about 35,000 in winter.
The June 13 meeting was a regular public meeting to discuss issues in the area overall, not specially set up for antiques dealers, but Mr Kleanthous said it would have been a good opportunity for them to air their views and it had not just been postponed, but cancelled.
The next scheduled meeting is not due until late October and most of that could be taken up with post-Notting Hill Carnival discussions.
Kensington and Chelsea Community and Police Engagement Group said the cancellation was because the borough commander could not attend, given "unprecedented pressures on policing during the summer" such as the Jubilee, Olympics and carnival.
But many traders wrote to the police to express their anger, with one - who had been robbed in Portobello - saying: "I really feel the police do not care. This was nasty - a vicious knife attack, and there will be more of the same. So what will you do about Portobello?"
Mr Kleanthous added that Portobello on Saturday should be treated like big sporting events, such as football matches, where although the clubs pay for policing inside, officers are out in force in the area around.
"We do not expect the police to be our personal bodyguards, but we expect them to police the street properly," he said, adding: "We used to have 12 officers on a Saturday, then down to eight and then four, now up to six, but it is totally inadequate."
Chris Hickey, of Central Gallery, one of the organisers of a special meeting on May 22 to discuss the policing, said local ward councillor Carol Caruana was trying to arrange a new meeting.
"Visibility is what we need to act as a deterrent," he added. "Now they only have four police officers for the whole street which stretches from Notting Hill Gate to Harrow Road, probably about two miles long, with 60,000 people on a Saturday coming down.
"An extra two are on now, but it is still not enough, because they always have to work in pairs. We are making progress but we have got to be patient. The police do a good job but could be better if they had more resources. They don't seem to prioritise this district - you go to a football match and the street is jam-packed with lots of people and police, but here it is like an event but isn't treated that way."
Pay for Policing
Mr Hickey has been given costs of 'buying in' extra police cover should traders wish to pay for it, and feels it could be feasible. Dealers are hoping a local businessman's interest in funding extra CCTV coverage will be agreed with the council.
A Met Police spokesman told ATG: "We continue to liaise with the market traders and address where possible any concerns raised.
"Public meetings are regularly held and are one forum used to air any community concerns. We remain serious in our intention to listen to these concerns - regrettably at times other policing issues facing the borough must take precedence.
"As a result of listening to the market traders' concerns, a visible policing presence continues to be maintained and is currently enhanced in and around the market area every Saturday."
But the Met Police have indicated to ATG that fears of violent robberies are overblown.
Chief Inspector David Tait said: "While there has regrettably been a slight increase in reports of burglary from antique shops in Portobello Road over the last 12 months (two between June 2010/11 and five between June 2011/12), none have involved violence and thankfully no victims of crime were physically injured.
"There has been no increase in offences of commercial robbery either against local antique shops or market traders in Portobello Road - and indeed there have been no such offences reported over the past two years.
"We are, however, currently investigating a recent allegation of robbery in which a jewellery trader was robbed in the local vicinity as he walked back to his car."