The RSPCA wants to be allowed to enter private property to seize pets in England and Wales.
The charity is in talks with the Government and police chiefs to negotiate new powers which will allow it to enter gardens, sheds and outhouses without an officer present.
Under current rules the RSPCA has to contact the local police force and wait for an officer to arrive if they believe an animal is in distress on private property.
But if granted special statutory powers, its 33 officers would be able to remove animals from private land without police permission – though the powers do not extend to entering a private home.
The RSPCA said it would be “seeking the power to seize animals in distress” rather than waiting “for the police and a vet which could prolong an animal suffering”, reported The Telegraph.
One backbench MP denounced the move, telling the newspaper: “RSPCA is a welfare charity not a private police force”.
The charity has come under heavy criticism for its tactics in recent years as it has carried out numerous private prosecutions against alleged animal abusers.
In November last year, a cross-party group of MPs published a report which said the RSPCA was “targeting vulnerable, ill and elderly people” and taking away their pets.
UK news in pictures
The new powers are currently being discussed with the National Police Chiefs Council, the Department for the Environment, Food and Rural Affairs and the Welsh government.
A source at the charity told the Telegraph that if the negotiations are not a success they will consider applying to individual local councils for statutory powers instead.
But they were keen to avoid the scenario where they had a “patchwork quilt” of powers in some areas and not in others, the source added.
The source said the idea was coming at a time when police budgets were stretched and “the last thing police want to do is turn up to help with an animal welfare case”.
But Tim Bonner, the chief executive of the Countryside Alliance, is not convinced.
He said: “You dress this up it can mean only one thing.
“The RSPCA wants statutory powers of entry on to private property and intends to use its huge £140 million annual budget in pursuit of those powers.
“Not happy with being moral arbiter, investigator and prosecutor of criminal offences the RSPCA now wants the power to enter your land and access your garden if it believes an offence is being committed.
“To even suggest that the state should entrust an organisation this flawed with far reaching and fundamental powers over its citizens shows how deluded the RSPCA is, but do not expect any dawn of reality.”