The Government is facing pressure from police and prosecutors to challenge the perceived leniency of a jail term imposed on a terrorist who planned to kill British troops in Afghanistan.

The 4½ year sentence given to Sohail Qureshi when he pleaded guilty to terrorism charges at the Old Bailey this week was greeted with anger by those who had brought the case to court. Peter Clarke, Assistant Commissioner for Specialist Operations at Scotland Yard, described him as “a trained and committed terrorist” and expressed surprise at the sentence.

Qureshi, 30, a dentist, who speaks five languages, admitted his offences after a rare legal procedure that led to him being told in advance what the maximum sentence would be if he pleaded guilty and avoided a full trial. He will serve half the 54-month term and, because he has spent 14 months on remand, will be free in just over a year.

The Timeshas learnt that, after liaising with police, the Crown Prosecution Service is expected to refer the case to Baroness Scotland of Asthal, QC, the Attorney-General, asking her to appeal against the sentence on the ground that it is “unduly lenient”.

If the appeal goes ahead it will be the first time that a sentence in a terrorist case has been challenged in such a way.

Sources close to the case told The Times that had Qureshi been convicted after a trial, they would have expected him to receive a sentence of 10 to 15 years.

Qureshi was the first person to be convicted for the offence of preparing to commit terrorist acts, under Section 5 of the Terrorism Act 2006. Counter-terrorism officials are particularly concerned that his sentence will send out a signal that the offence is regarded by the courts as a minor one. The maximum term is life imprisonment.

Qureshi, from Forest Gate, East London, was stopped at Heathrow in October 2006 as he tried to board a flight to Pakistan with £9,000 cash, military equipment in his luggage and combat manuals on a computer hard drive.

Searches at his home recovered pictures of Qureshi, who was born in Pakistan, carrying an array of assault rifles on previous visits to the region.

In an e-mail to a friend that was retrieved from his computer he said: “Make dua [pray] that I will kill many.” He said he was going to take part in “an operation”, possibly in Afghanistan. Qureshi had also been in e-mail contact with Samina Malik, a shop assistant at a Heathrow airside branch of W H Smith, to ask about security arrangements.

Qureshi and Malik were arrested and it was planned that they should stand trial together. However, Malik, 23, stood trial alone last year.

She was given a nine-month suspended sentence for possessing items useful to terrorists. Her link to Qureshi was not disclosed to the jury in her trial.

When Qureshi’s case came to court on Monday his lawyers sought an “advance sentence indication” – notifying the court that he would be prepared to plead guilty but would like to know the maximum sentence he would face if he did so.

The procedure is known as a Good-year hearing after the name of a case at the Court of Appeal in 2005 that set down formal guidelines for its conduct.

Defence and prosecution lawyers submitted an agreed written basis of plea to Judge Brian Barker, the Common Serjeant of London. On Tuesday he told Qureshi that he would not impose a sentence longer than six years.

Qureshi’s lawyers then spent two hours with their client before he returned to court and entered a formal guilty plea to three charges of acts preparatory to terrorism and possessing items of use to terrorists.

The judge then sentenced Qureshi, telling him that although all terrorist offences were grave, he believed that his crimes were at the lower end of the scale. Imposing the 4½year term, the judge said: “You were ready for terrorist operations overseas but there is no specific indication of what they are or where they might be.”

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