Russia had spied on Yulia Skripal for FIVE YEARS before attack and trained its agents to put Novichok on door handles, explosive British intelligence dossier reveals

RUSSIA has been hacking Salisbury victim Yulia Skripal’s email since 2013 and testing Novichok on door handles – an explosive UK intelligence dossier has revealed.

Previously classified details were published by the Government today to prove beyond doubt the Kremlin was behind the attempted killing of Yulia and her father Sergei.

A bombshell letter from National Security advisor Sir Mark Sedwill to NATO chief Jens Stoltenberg reveals Russia trained up a number of assassination squads in the use of deadly nerve agents during the 2000s.

It adds this programme “subsequently included investigation of ways of delivering nerve agents, including by application to door handles”.

Tests on the Skripals' house in Salisbury found the highest concentration of Novichok on their door.

Sir Mark adds that Britain has “information” that Russian intelligence services have been monitoring the Skripals for at least five years.

He says that as far back as 2013, email accounts belonging to Yulia were “targeted by cyber specialists” from the GRU – Moscow’s military intelligence directorate.

The explosive detail will threaten a new bitter war of words with the Kremlin.

It comes with Russia stepping up its bid to discredit Britain – and stop the West from monting military action against its allies in Syria.

Sir Mark said Russia has maintained and built a deadly arsenal of chemical weapons long after the collapse of the Soviet Union.

His letter sets out that the Soviets developed Novichok nerve agents at the State Institute for Organic Chemsity and Technology at Shikhany near Volgograd.

The codeword for the offensive chemical weapons programme was ‘Foliant’, and he adds: “In the mid-2000s, President Putin was closely involved in the Russian chemical weapons programme.”

Sir Mark says: “We continue to judge that only Russia has the technical means, operational experience and motive for the attack on the Skripals and that it is highly likely that the Russian state was responsible.

“There is no plausible explanation.”

The letter was published today following the findings from global watchdog OPCW yesterday that a nerve agent with “almost complete absence” of impurities was used in the Salisbury attack.

Following the outcome, Boris Johnson said in a statement: “There can be no doubt what was used and there remains no alternative explanation about who was responsible – only Russia has the means, motive and record.