“Laying the Brexit Party wreath at the Epping Remembrance Parade in honour of those that died fighting for our Freedom,” he wrote above the footage on Twitter.
However he was quickly accused of attempting to politicise Remembrance Sunday only weeks before the general election on 12 December.
The Royal British Legion had appealed to party leaders to ”ensure that no election candidates or ministers are seen to use their involvement with a Legion event or facility to party political or personal advantage.”
“In incredibly poor taste to lay the wreath of a political party in uniform,” wrote on Twitter user, Sam Holland. “No surprise it was a Brexit Party candidate essentially insinuating the party is somehow representative of the UK military. Crass, ignorant and offensive.”
Others ridiculed the 45-year-old businessman as “full kit w***er” and a “Walter Mitty”, referring to the fictional character who fantasises about being a wartime pilot.
The video was first highlighted by anonymous Twitter user under the name “Otto English”, who wrote: “The general consensus is that the uniform is all wrong unless he’s heading a local CCF (Combined Cadet Force). And if that’s the case he certainly shouldn’t be laying a wreath on behalf of The Brexit Party.”
Mr Selkus, who was at the time the official Brexit Party candidate for Epping Forest, responded online that he “had every right to be there.”
He added: “The Conservative and Labour Party also laid wreaths at the same parade.”
However, he was dropped as an official candidate following Nigel Farage’s decision not to stand against Conservative MPs – in this case Eleanor Laing, who has represented the constituency since 1997.
Brexit Party spokesman Gawain Towler said there was nothing wrong with Mr Selkus’ behaviour, but added: “I am not going to waste my time defending a former candidate.”
He said: “There are plenty of former soldiers who wear uniform. All over the country people from political parties put wreaths down. Is this a problem? No.”
Army dress regulations allow retired officers to wear uniforms on Remembrance Day.
Mr Selkus, who runs a business selling wood veneer products, said he served in the 3rd Battalion, The Royal Regiment of Fusiliers, in Germany in 1992 and the Territorial Army London Regiment before his retirement in 1998, when he was “Captain of the Reconnaissance Platoon, D Company, The London Scottish”. The London Gazette confirms he served with the TA London Regiment and rose to the rank of lieutenant at least before his retirement.
He wrote that he had been “shattered” to learn of Mr Farage’s decision to stand down more than 300 candidates.
”I don’t understand why Nigel Farage has betrayed my incredible volunteers and thousands of constituents who will have no one to vote for,” he said.
In August Mr Selkus boasted that he had taken his children to the Tower of London “to see how the UK used to deal with traitors.”’