Boris Johnson hinted at a fresh crackdown on terrorism on Sunday when he said the government was ready to act on any lessons that emerge from the stabbing attack in a Reading park once police have completed their investigations. In a broadcast statement recorded in Downing Street and issued on Sunday lunchtime, Johnson said he was “appalled and sickened that people should lose their lives in this way”. “We now have someone in custody. The police must now get on with their job, get to the bottom of exactly what happened, so it would be difficult to comment in detail,” he said. “Except to say this: that if there are lessons that we need to learn about how we handle such cases, how we handle the events leading up to such cases, we will learn those lessons, and we will not hesitate to take action where necessary.” The prime minister added: “If there are changes that need to be made to our legal system to stop such events happening again, we will not hesitate to take that action – as we have before, you will recall, over the automatic early release of terrorist offenders.” Police have said the stabbing rampage, in which three people were killed and at least three others injured, is being treated as a terror incident. A 25-year-old Libyan national is being held. It was unclear what legal changes Johnson had in mind. The home secretary, Priti Patel, is known to be keen to tighten the rules around deportations of foreign offenders, to make it easier to remove those convicted of terror offences, and limit the terms on which they can be challenged in the courts. However, Whitehall sources said it was unlikely that any policy change would affect the fact that it is impossible to deport prisoners to what is essentially a failed state. The man named as the suspect, Khairi Saadallah, would not in any case have been an automatic candidate for deportation, since his sentence for previous offences was less than the 12 months that lays an obligation on the home secretary to make a deportation order, under the UK Borders Act 2007. As well as the restrictions on deportation, any review could consider the supervision of prisoners after their release, to examine whether there were gaps in provision that could be closed. Keir Starmer said he would be willing to work with the government to assess the need for any changes to the legal framework. “It’s very important that the investigation runs its course, but I will want to work with the government in response to this – to look at whether there’s lessons that can be be learned, whether there are changes in the law,” the Labour leader told ITV News. He added: “I think as a constructive opposition we will want to speak to the PM to discuss how together we can learn from the response, improve the response. The investigation must be completed, but of course, this is not a time for party politics.” Johnson’s government has repeatedly taken a tough line on law and order, with Patel warning criminals in her party conference speech last October: “We are coming after you”. After the attack in Fishmongers’ Hall in London a month later, by a convicted terrorist who had been released on licence, Patel swiftly announced changes to the early release policy for convicted terrorists. That resulted in the publication of the counter-terrorism and sentencing bill, which is making its way through the House of Commons. The bill introduces mandatory minimum sentences of 14 years for the most serious terror offences, and limits the use of early release. At the time it was published, Patel also announced a review of the Multi-Agency Public Protection Arrangements (MAPPA) for monitoring terrorist offenders. The deportation of foreign nationals with terrorism convictions has been a consistent aim for successive governments, with home secretaries – in particular, Theresa May – railing against the constraints of human rights law. The Labour government struck a memorandum of understanding in 2005 with Libya’s then leader Muammar Gaddafi to allow “deportation with assurances”, under which Libya pledged not to mistreat returned nationals. But in 2008, the court of appeal ruled that such assurances were insufficient. Since then, the collapse of Libya into civil war after the fall of the Gaddafi regime has deportation even more difficult to square with the European Convention on Human Rights (ECHR), to which the UK is a signatory. The Conservative manifesto pledged to update the Human Rights Act, which enshrines the ECHR in British law. When a deportation flight to Jamaica was halted by a judicial review in February, Johnson’s adviser Dominic Cummings dismissed the concerns of human rights campaigners as a “Westminster bubble” issue, and pledged to overhaul the use of judicial review.