JEREMY Corbyn has been severely condemned for appointing the disgraced Scottish peer Lord Watson of Invergowrie to his frontbench team with the Conservatives claiming that Labour’s credibility was now “in tatters”.

The 66-year-old convicted fire-raiser returned to frontline politics as Labour’s education spokesman in the House of Lords, a decade after he served eight months in prison for setting fire to a curtain in a room at Edinburgh’s Prestonfield House hotel.

The announcement marked the end of a turbulent first week for Mr Corbyn’s leadership and is the latest row to engulf the Lords this year.

In July, Scots peer Lord Sewel of Gilcomstoun resigned after footage was published of him in a tabloid newspaper allegedly snorting cocaine with prostitutes.

The Electoral Reform Society reported the following month that 62 peers had racked up £360,000 in attendance fees and expenses over the past five years despite failing to take part in any votes.

The Conservative Government has also been criticised for giving a peerage to the Scots businesswoman Michelle Mone.

The strongest condemnation of Mr Corbyn’s decision to appoint Lord Watson came from Lord Tebbit, the former Tory Chairman, who said: “The appointment seems to confirm that Mr Corbyn has a fondness for people with criminality in their blood. He has a fondness for Adams and McGuinness, for Isis and for Argentinian dictators.”

The peer and his wife were seriously injured in the IRA bombing of Brighton’s Grand Hotel in October 1984. During the Falklands War in 1982, Lord Tebbit was Employment Secretary in Margaret Thatcher’s Government.

Gerry Adams, the Sinn Fein leader, was among the first to congratulate Mr Corbyn on his leadership victory last Saturday, describing the Islington North MP as a “good friend of Ireland and of the Irish peace process”.

Mr Corbyn is a supporter of a united Ireland, he opposed the Falklands War and has spoken out against the UK bombing of Islamic State targets in Syria.

Asked if the Labour leader’s appointment brought politics into disrepute, Lord Tebbit replied: “Mr Corbyn brings politics into disrepute.”

A spokesman for the Scottish Conservatives said: “Across Scotland, people will be staggered by this decision. Coming after Mr Corbyn appointed an IRA sympathiser as Shadow Chancellor, it amply demonstrates that Labour’s claim to credibility is now in tatters.”

The SNP branded Lord Watson’s return to full-time frontline politics “bizarre”.

A spokesman said: “It reflects how Jeremy Corbyn seems to be scrambling around for people to work with, which in turn is further proof of the deep divisions within the Labour Party.”

But Labour HQ strongly defended Lord Watson’s appointment. A spokesman said: “Our position is Mike has been convicted, he has served his time and has been rehabilitated…It is right he should be allowed to play a full part in public life.”

He added: “Jeremy is a strong believer in rehabilitation. If people have served their time and you stop believing in rehabilitation, it would leave us as a much poorer country.”

In 2005, Lord Watson admitted setting fire to a curtain when he attended The Herald’s Scottish Politician of the Year awards.

The former Scottish Culture Minister, who served in Jack McConnell’s Holyrood government, at first ‘’categorically’’ denied any wrongdoing but later pleaded guilty to a charge of wilful fire-raising when he appeared at Edinburgh Sheriff Court in September 2005.

The peer was jailed by the sheriff for 16 months for his ‘’deliberate and dangerous’’ actions. He served just eight, being released in May 2006.

Lord Watson resigned from the Scottish Parliament as well as director of Dundee United. Controversially, Westminster rules meant a life peer could not resign from the Lords and so the ex-Glasgow MP kept his seat on the red benches.

The former Minister was expelled from the Labour Party in September 2005 following his conviction and imprisonment but was re-admitted to in July 2012.

A party spokesman, when asked why he had taken the education brief, a devolved issue, said that the appointment of Baroness Maggie Jones, Labour’s previous Education Spokeswoman in the Lords, to cover the environment brief, had freed up the education portfolio. Lord Watson had requested this role and his request had been accepted.

The creation of an overwhelmingly pro-Trident shadow defence team, which is led by Maria Eagle, who supports maintaining the nuclear deterrent as do former Defence Ministers Kevan Jones and Lord Touhig, has led to suggestions Mr Corbyn, an ardent opponent of nuclear weapons, will concede to a pro-Trident defence policy.

Mr Corbyn’s spokesman described Labour’s new frontbench as “inclusive across the party”.

Meantime, in the wake of hints that disenchanted Labour MPs might defect to the Liberal Democrats, Sir Vince Cable, the former Business Secretary, said progressive centre-left politicians from Labour and the Lib Dems needed to “come together” to stop the Tories monopolising power following Mr Corbyn’s victory.