Council chiefs are being urged to launch an investigation after metal spikes were installed outside a luxury block of London flats to deter homeless people from sleeping in the doorway.

The inch-high studs in the main entrance to the deluxe privately owned apartments in Southwark Bridge Road have provoked outrage as homelessness charities slammed the "inhumane" practice.

The spikes, which are thought to have been installed in the past month, are in a sheltered alcove opposite a hostel for homeless people with mental health problems.

Controversy grew over the weekend after a picture of the metal spikes was posted online, sparking outrage from people who compared them to the spikes used to keep birds away from buildings. David Wells said on Twitter: "These Anti homeless studs are like the spikes they use to keep pigeons off buildings. The destitute [are] now considered vermin."

By Saturday night a petition to remove the studs was approaching 1,000 signatures and several people had lodged formal complaints with Southwark council.

Katharine Sacks-Jones, head of policy and campaigns at homelessness charity Crisis, said: "It is a scandal that anyone should sleep on the streets in 21st-century Britain. Yet over the last three years rough sleeping has risen steeply across the country and by a massive 75% in London.

"Behind these numbers are real people struggling with a lack of housing, cuts to benefits and cuts to homelessness services to help them rebuild their lives. They might have suffered a relationship breakdown, a bereavement or domestic abuse. They deserve better than to be moved on to the next doorway along the street. We will never tackle rough sleeping with studs in the pavement. Instead we must deal with the causes."

A spokeswoman for Southwark council said it would look into any official complaints but that there was little it could do unless the studs were in breach of planning regulations.

Councillor Peter John, leader of the council, said: "Southwark council is aware of concerns raised regarding the installation of spikes outside a privately owned building on Southwark Bridge Road to prevent rough sleeping.

"The council can look into health and safety or planning concerns that are reported to us. With regards to people sleeping rough the council has a dedicated officer who works closely with organisations like St Mungo's [a homelessness charity], who have a 'no second night out' policy to ensure rough sleepers are found shelter and support."