The suspects of the Salisbury nerve agent attack say they visited as tourists to see the city's cathedral.
The men, who said their names were Alexander Petrov and Ruslan Borishov, told Russian state-funded news channel RT that they travelled to the "wonderful city" after recommendations from friends.
One hundred and twenty UK military personnel are currently helping with the general decontamination of the city, following the poisoning of former Russian double spy Sergei Skripal and his daughter Yulia. Both have since recovered.
Extra British personnel were deployed to begin decontamination work on Sergei Skripal's home in Salisbury last week.
Downing Street described the pair's interview as "deeply offensive to the victims and loved ones of this horrific attack" and accused Russia of "lies and blatant fabrications".
In a translation from Russian, the pair told RT editor-in-chief Margarita Simonyan that they worked in the fitness industry.
The broadcaster quoted Petrov saying the pair arrived in London on 2 March, attempted to visit Salisbury on 3 March but were thwarted by snow and instead returned the following day when it was warmer to see the cathedral.
He said: "Of course, we went there to see Stonehenge, Old Sarum, but we couldn't do it because there was muddy slush everywhere. The town was covered by this slush.
"We got wet, took the nearest train and came back [to London]."
Boshirov said: "Our friends have been suggesting for a long that time that we visit this wonderful town [Salisbury]."
Petrov added that they went to visit the "famous" Salisbury cathedral, that is "not only famous in Europe but the whole world."
It is the men's first interviews since being named as the prime suspects by UK police and denied carrying women's perfume, after police discovered a counterfeit bottle that contained a "significant amount" of the nerve agent Novichok.
Boshirov, who said his life had been turned "upside down", acknowledged they may have been near Mr Skripal's house but they did not know where it was.
The pair also asked for an apology from the UK authorities, adding:
"We just want this to be over."
On Wednesday, Russian President Vladimir Putin described the pair as "ordinary civilians".
UK authorities believe the men smeared Novichok on a door handle at Mr Skripal's home in Wiltshire.
Tests on the east London hotel room where the suspects stayed showed traces of Novichok.
Scotland Yard said it still believed the pair were using aliases after the men claimed Petrov and Boshirov were their real names.
The Prime Minister's official spokesman said: "The lies and blatant fabrications in this interview given to a Russian-state sponsored TV station are an insult to the public's intelligence.
"More importantly, they are deeply offensive to the victims and loved ones of this horrific attack. Sadly, it is what we have come to expect.
"An illegal chemical weapon has been used on the streets of this country. We have seen four people left seriously ill in hospital and an innocent woman has died. Russia has responded with contempt."
John Glen MP for Salisbury and South Wiltshire said the interview was "not credible".
Officers linked the attack on the Skripals to the poisoning of Dawn Sturgess and Charley Rowley in nearby Amesbury. Mrs Sturgess died a week after falling ill.
Meanwhile, the Russian military's biggest training exercise since the end of the Soviet Union is underway.
'Vostok 2018', which is being run with China, has been described by NATO as a rehearsal for "large-scale conflict".
It is claimed there are 300,000 Russian soldiers taking part, with more than 1,000 aircraft, 36,000 vehicles and 80 ships also involved.
Mr Putin delivered a speech to his soldiers at Vostok 2018, promising that Russia will "continue to strengthen" its armed forces with "cutting edge arms and equipment".