The investigation was carried out by the British Parliament’s Intelligence and Security Committee and is largely based on closed-door testimony by senior officials from Britain’s intelligence community. It reportedly contains evidence from Russia experts in agencies such as the Security Service (MI5), the Secret Intelligence Service (MI6) and the Government Communications Headquarters (GCHQ).

According to media reports the probe was completed in March of this year and underwent a redaction process to safeguard intelligence methods and sources. On October 15 it was submitted to Downing Street and on October 17 it reportedly landed on the desk of British Prime Minister Boris Johnson. British opposition politicians allege that even sensitive reports are usually made public no later than 10 days after they are submitted to Downing Street, which means that the document should have been released prior to October 28.

Some fear that, with Parliament about to suspend operations on Tuesday, in anticipation for December’s general election, the report will effectively remain hidden from public view until the spring of 2020. On Friday, Labour Party leader Jeremy Corbyn publicly urged the government to release the report and claimed that the prime minster may have “something to hide”. But cabinet minister Andrea Leadsom argued that it is not unusual for parliamentary committee reports to remain in the government’s hands until they are properly evaluated. “The government has to respond properly, it cannot respond in haste”, said Leadsom.