Home Secretary Suella Braverman failed to take responsibility over placing asylum seekers in hotels, Caroline Lucas has claimed.
An Observer investigation revealed that dozens of asylum-seeking children have been kidnapped from a hotel in Hove and trafficked as far away as Scotland.
The newspaper claimed that around 600 unaccompanied children have passed through the hotel over the last 18 months, with 136 reported missing.
About 79 of those remain unaccounted for, the Observer reported.
MP for Brighton Pavilion Caroline Lucas said: "The horrors of children going missing and reportedly being abducted are deeply alarming.
"The Home Office practice of directly placing children in these hotels is dangerous and I've been raising concerns for weeks because the Home Secretary is failing to take any responsibility, refusing to answer even basic questions, and children are still at serious risk.
"The use of these hotels must end now. What's more, we need a full and comprehensive investigation involving the Home Office, police and social services, and for these missing children to be found."
Peter Kyle, MP for Hove, and Lloyd Russell-Moyle, MP for Brighton Kemptown, joined with Labour councillors in the city in demanding an inquiry and for hotels accommodating unaccompanied children to be closed with immediate effect.
An Observer investigation revealed that the Home Office was warned by police that vulnerable occupants at the hotel in Hove would be targeted by criminal networks.
A whistleblower who worked for Home Office contractor Mitie told the newspaper: “Most of the children disappear into county lines.
“The Albanian and Eritrean gangs pick them up in their BMWs and Audis and then they just vanish.”
The whistleblower told the Observer he had repeatedly told the Home Office about his concerns but to no avail.
A spokesman for the Home Office said: “Local authorities have a statutory duty to protect all children, regardless of where they go missing from.
“On the concerning occasion when a child goes missing, they work closely with other local agencies, including the police, to urgently establish their whereabouts and ensure they are safe.
“Ending the use of hotels for unaccompanied asylum-seeking children is an absolute priority, and we have robust safeguarding procedures in place to ensure all children in our care are as safe and supported as possible as we seek urgent placements with a local authority.”