Marco Rubio vents via Twitter

The 44-year old Rubio - who quit the race for the Republican nomination after losing his home state of Florida to Donald Trump in mid-March - started his barrage late on Monday, tweeting a link to a Washington Post story headlined, "5 people who are never going to be Donald Trump's vice president."

The senator - who it seems has taken personal control over his own Twitter account since his presidential run ended - added his own commentary on the Washington Post's sourcing. "Funny to read about unnamed ‘people close' to me who claim to know my thinking on future plans," he wrote on Twitter. "They just make it up."

The senator also linked to a separate story - published in October - saying that didn't hold water either. "Flashback to another article quoting a ‘longtime friend' saying I ‘hate' Senate," Rubio wrote on Twitter. "Words I have NEVER said to anyone."

'Betwixt and between?'

The Washington Post article reported a source saying the senator was "betwixt and between when it comes to his next move." Rubio, meanwhile, said he'd made clear his plans to give up his position as Florida Senator and take time out from politics "like 10,000 times."

Rubio then joked that this political time-out would surely scupper any presidential ambitions for 2020 - an ironic reference to Donald Trump rewriting the rulebook and emerging as Republican frontrunner despite holding no place in US politics before the primaries.

An absentee politician

The Washington Post interviewed Rubio, friends and staffers for the article and also examined his nearly five-year record in the Senate: votes, speeches, legislation and committee hearings. It noted that he had skipped 10 percent of them in 2014, making him one of the most absent senators, according to statistics kept by website GovTrack.us.

Rubio was also often absent in committee work, in 2014 missing 34 of 68 committee hearings and meetings in the Foreign Relations committee, according to his office's tally.

Rubio's absence from Senate debates had raised some eyebrows, suggesting he had staked all on winning the Republican candidacy. The Post article writes: "Rubio is not a quitter, the argument goes…In fact, that's precisely why he's quitting this place."

"That's why I'm missing votes. Because I am leaving the Senate. I am not running for re-election," Rubio said in the last Republican debate. This after Trump had mocked him for his unusual number of absences during Senate votes.

Rubio came under attack from rivals who dubbed him an absentee federal employee. Former Florida Governor Jeb Bush has said senators who miss work should have their pay docked.

"It's just, kind of, like, dude, you know, either drop out or do something," Jeb Bush told New York University College Republicans earlier this month.

Rubio last week said that he would support Trump - the only contender left for the Republican nomination - though not campaign for him. He said he continued to have policy differences with Trump.

Rubio and Trump had some bitter exchanges in the weeks leading up to Rubio's devastating loss in the primary in his own state.

The former presidential candidate signed off his hour-long online tirade by saying: "Enough for one night. Twitter isn't something you should just rush back into."