US House Judiciary Committee Chairman Jerrold Nadler issued a subpoena on Friday to obtain the full Russia investigation report by Special Counsel Robert Mueller, saying he cannot accept a redacted version that "leaves most of Congress in the dark." "My committee needs and is entitled to the full version of the report and the underlying evidence consistent with past practice. The redactions appear to be significant. We have so far seen none of the actual evidence that the Special Counsel developed to make this case," Mr Nadler said in a statement, the day after the release of 448-page report. A redacted version of Mr Mueller's report released on Thursday concluded that Russia interfered in the 2016 US election to help Donald Trump defeat Hillary Clinton. But it said there was no criminal conspiracy or co-ordination by Mr Trump or members of his campaign team. Democrats have vowed to continue pursuing the full truth about allegations of potential obstruction of justice by the Trump administration. The report provided extensive details on Trump's efforts to thwart Mr Mueller's Russia investigation, giving Democrats plenty of political ammunition against the Republican president but no consensus on how to use it. The 448-page report painted a clear picture of how Mr Trump had tried to hinder the probe but did not conclude that he had committed the crime of obstruction of justice, although it did not exonerate him. The report blacked out details about secret grand jury information, US intelligence gathering and active criminal cases as well as potentially damaging information about peripheral players who were not charged. Half a dozen former Trump aides were charged by Mr Mueller's office or convicted of crimes during the 22-month-long investigation. The Democrats' subpoena gives US Attorney General William Barr until May 1 to produce the materials requested. Democratic leaders played down talk of impeachment just 18 months before the 2020 presidential election, even as some prominent members of the party's progressive wing, most notably US Representative Alexandria Ocasio-Cortez, promised to push the idea.