Ministers face "real anger" if they do not overhaul "failed" policies aimed at dealing with illegal Traveller sites, Tory MPs have warned.
Tory former ministers Andrew Selous, Mark Francois and Tim Loughton were among those pushing for reform, arguing action is needed to help both the Traveller and settled communities.
They favour emulating Ireland by making acts of deliberate trespass a criminal offence, referred to as the "Irish option", in a bid to protect land and public sites.
Mr Selous also said UK Government ministers and officials should be "hanging their heads in shame" over the conditions on some sites, labelled a public health risk by fellow Tory John Howell (Henley).
They raised concerns as the Government prepares its response to a consultation on the law and powers to deal with unauthorised caravan sites and developments.
Speaking in the Commons, Mr Francois (Rayleigh and Wickford) said: "What we're asking for essentially is the Irish option based on the fact in 2002 Ireland changed the law to make acts of deliberate trespass a criminal offence."
Mr Francois added: "There will be real anger in this place if, as a result of this consultation, the Government doesn't do something meaningful – rather than some very minor tweak in the law as window dressing – to address this problem, such that we would see a real decrease in the incidents in the next few years."
Mr Loughton earlier said of illegal Traveller encampments: "Invariably when they leave, they leave behind a trail of devastation of rubbish which costs the local taxpayer an enormous amount to clear up.
"Is not the change in the law that we need that, rather than have to point to a single person who caused the access damage, that collectively any group of Travellers illegally encamped should be liable for fines and compensation – which involves confiscation of, often, quite valuable vehicles as well – and they might then get the message they cannot continue with impunity trampling over the rights of local people."
Leading the debate on Gypsies and Travellers, Mr Selous said the "time for endless, constant reviews is over".
He said: "Fair and decent-minded people who are fed up with living in fear, of seeing atrocious living conditions in their areas which often become ungoverned space where modern slavery and other crime flourishes, want action now, not constant reviews."
Mr Selous pushed the case for integration, arguing the policy of segregation has "demonstrably failed" before telling MPs: "We also need trespass to be made part of the criminal law, as it is in Ireland."
Other ideas suggested included having a registered landowner for Traveller sites.
Mr Selous earlier questioned if the Government's current policy works well for Travellers themselves, raising education concerns before saying: "Travellers and the families that Travellers illegally let their caravans to on Travellers' sites often have no proper sewerage, water or heating and there is no proper mechanism in place to ensure decent standards of housing.
"The whole situation is a complete disgrace in the United Kingdom in 2018, and Government ministers and officials responsible for this policy area should be hanging their heads in shame."
For the Government, Communities minister Kit Malthouse said the majority of the Traveller community are "decent, law-abiding people", adding he was "extremely concerned" about issues raised in the debate – including the conditions and activities on certain sites.
He said the Government's recent consultation received more than 2,000 responses.
On the "Irish option", Mr Malthouse told MPs: "The Communities Secretary (James Brokenshire) has recently met the Irish government to discuss their approach to trespass and unauthorised encampments.
"We will, however, provide a formal response to the consultation in due course."
He noted there are "pros and cons" to the approach.
Mr Malthouse went on: "(Mr Selous) has expressed his frustration with Government action thus far and calls for significant change.
"I have no specifics for him tonight, but I fervently hope that, through my actions and the actions of the department over the months to come, we can obviate the need for a fourth such debate."