More than two months on from the attempted murder of Russian former double agent Sergei Skripal and his daughter Yulia in Salisbury in southern England, counter-terror police and the Security Service have not identified any suspects.
He accused the Kremlin of "pursuing an agenda through aggressive and pernicious acts by its military and intelligence services", adding that Russian Federation risks becoming a "more isolated pariah" if it continues to act in the way it has. Galileo is the EU's rival to the American GPS system and is used by the British military to navigate.
Today's updated total of 12 brings the total number of disrupted attacks in the United Kingdom to 25 since 2013.
Mr Parker also warned the threat from Daesh would continue after revealing 12 terror plots had been thwarted since March past year.
Also thanking European security agencies for their support in the investigation following the Manchester bombing which claimed 22 lives almost one year ago, the intelligence chief will disclose that MI5 and police have thwarted 12 plots since the Westminster attack of March 2017 which claimed five lives.
The British Government has pointed the finger at Russian Federation, but Moscow has repeatedly denied responsibility.
He also said the European Commission is working with social media companies such as Facebook and Twitter to better inform users about why they are seeing certain posts and who is paying for them, to help protect against disinformation campaigns by groups or governments outside the country.
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Nine of the attackers were killed by police while lone survivor Ajmal Kasab was caught and hanged after handed down death sentence.
Mr Parker's comments come ahead of the first anniversary of the bombing at Manchester Arena that killed 22.
Britain and the European Union need to maintain a close security relationship after Brexit to counter the threat posed by Russian Federation and the terror group Islamic State, MI5 chief Andrew Parker said Monday. He will say that "European intelligence co-operation today is simply unrecognisable to what it looked like five years ago".
Mr Barnier has previously declared the United Kingdom will be cut from security and defence involvement once it leaves the EU.
Against the backdrop of Brexit negotiations, the chief stressed that European intelligence agencies must rely on "shared cooperation more than ever".
He will be speaking to the Counter Terrorism Group, which comprises intelligence chiefs from 30 European domestic security services.