Cat flaps should be banned to help preserve the UK’s declining number of garden birds, according to a Conservative former minister.

Lord Blencathra said there is “no justification whatsoever” for cat owners to take a “laissez-faire attitude” by letting their pet “go in and out when it pleases”.

He also backed calls for outdoor cats to be required to wear collars and bells, as he pointed to research suggesting this helps reduce the number of birds killed by felines.

Lord Blencathra’s cat flap ban suggestion came as peers supported a proposed law to create two new offences of cat and dog abduction in England and Northern Ireland.

Animals are regarded as property under existing theft legislation, with campaigners arguing for the emotional value of pets to be recognised as well as the distress caused if they are stolen.

The Bill would make it an offence to take a cat or dog from the lawful control of another person, with offenders facing a maximum prison sentence of five years.

It moved closer to becoming law after receiving an unopposed second reading in the Lords, having previously cleared the House of Commons.

Lord Blencathra offered his “full support” to the Bill before backing remarks made by Natural England chairman Tony Juniper for cats to wear bells.

He told peers: “All independent studies suggest that cats allowed out to wander at will kill about 260 million mammals per annum in the UK and 60 million garden birds.

“Of course there are other predators killing animals and birds, as the letters in the Telegraph this week have pointed out, but the contribution from roaming cats is massive and unnecessary.

“Studies by three UK scientists, and published in the journal of Applied Animal Behaviour Science, show that in the UK cats with bells killed 34% fewer mammals and 41% fewer birds.

“We need every measure we can to preserve our declining garden birds.

“So I would make collars and bells compulsory for cats let outside. But I would go further, my Lords, and I’d ban cat flaps completely.”

Lord Blencathra said animal welfare organisations had suggested cats should only be let out after the sun has risen or before it sets to avoid them targeting birds when they are feeding.

He added: “There’s no justification whatsoever for cat owners taking a laissez-faire attitude and letting a cat go in and out when it pleases.

“Don’t call yourself a cat lover if you have no idea where your cat goes at night, where it can be attacked, run over, catch fleas, diseases and kills precious wildlife.”

Lord Blencathra earlier suggested possible changes to the penalties, including a guaranteed £5,000 fine irrespective of an individual’s ability to pay and harsher punishments if two or more people are involved.

He said the existing penalties in the Bill are “theoretically quite good”, adding: “But they will never, ever happen because once the rather wet, woke, liberal Sentencing Council produce their sentencing guidelines no-one will ever get the maximum and the average sentence will be watered down to a few hundred pounds and it’ll not be paid.”

Shadow environment spokeswoman Baroness Hayman of Ullock offered Labour’s support to the Bill and noted she was “interested” to hear Lord Blencathra’s suggestions on cats.

Lady Hayman said she wanted to “stand up” for her own cat, joking he is “not a very prolific killer” and he is “rather frightened” of birds following an “encounter” with a hen.

Environment minister Lord Douglas-Miller said: “The Government strongly supports this Bill. It represents another important step in our progress on animal welfare.”

On Lord Blencathra’s comments, the minister said his officials recently met the Songbird Survival charity.

He said: “They heard about research by the University of Exeter which showed that owners can reduce their cat’s hunting by adjusting their cat’s diet or by spending short periods playing with them.”

Lord Douglas-Miller said the Government would continue to engage with the charity and its campaign to spread awareness.

The Bill will undergo further scrutiny in the Lords at a later date.

Annabel Berdy, senior advocacy and Government relations officer for Cats Protection, said: “The Pet Abduction Bill will give pets the full recognition they deserve and help stamp out the horrific trade in stolen pets which causes so much misery to owners and animals.”