The MP son of Neil Kinnock, the former Labour leader, has been publicly shamed by police for “non-essential” travel during the coronavirus lockdown after going to celebrate his father’s 78th birthday.

Stephen Kinnock, the MP for Aberavon in South Wales, posted a picture of himself sitting on a chair outside his parents’ London home, adhering to guidelines to stay two metres apart, as they marked the occasion with his wife, the former prime minister of Denmark, Helle Thorning-Schmidt.

Facebook Twitter Pinterest Helle Thorning-Schmidt visiting Neil and Glenys Kinnock on Saturday with her husband, Stephen. Photograph: Stephen Kinnock/Twitter

But officers from South Wales police, 150 miles away, rounded on him for the decision to go to see his family.

It was the latest example of lockdown enforcement tactics deployed by police across the country, who have broken up parties, deterred motorists and walkers with drones and dyed a lake black to put off swimmers under strict physical distancing rules.

In the tweet, with his parents sitting on their doorstep in the background, Stephen Kinnock wrote:

Stephen Kinnock (@SKinnock) Dad turned 78 today. Incredible, but true. @HelleThorning_S and I took a couple of chairs over, and sat in their front garden for a socially distanced celebration. As you do 🙂Happy birthday, mate. 🍰 🎁🏴󠁧󠁢󠁷󠁬󠁳󠁿 pic.twitter.com/ipGuN2WzsC

South Wales police replied with: “Hello @SKinnock we know celebrating your Dad’s birthday is a lovely thing to do, however this is not essential travel. We all have our part to play in this, we urge you to comply with @GOVUK restrictions, they are in place to keep us all safe. Thank you.”

South Wales Police | #StayHomeSaveLives (@swpolice) Hello @SKinnock we know celebrating your Dad’s birthday is a lovely thing to do, however this is not essential travel. We all have our part to play in this, we urge you to comply with @GOVUK restrictions, they are in place to keep us all safe. Thank you. ^cy

The MP then defended the move, saying he had been delivering “necessary supplies” and only stayed “long enough to sing ‘happy birthday’ to Dad”.

Stephen Kinnock (@SKinnock) I felt that this was essential travel as I had to deliver some necessary supplies to my parents. I stayed long enough to sing ‘happy birthday’ to Dad, and then I was off. All the best, Stephen.

Critics said the police were overzealous in publicly criticising the MP, as others warned they could could lose the respect of the public.

Don Morgan tweeted: “This looks very wrong ....focus on the big stuff … not trivia ... this will lose you public support at a time when it’s really going to be needed.”

Walkies Cleo added: “Looking after vulnerable relatives is indeed essential so well done Stephen. You delivered essential supplies, checked they were ok, all from a safe distance. @SWpolice you should be disgusted with your post, doing your force no favours and will lose all respect with public!!”

However, others agreed with South Wales police, saying the MP was setting a bad example to others. Bleddyn Dunn wrote: “What’s the travel distance? Why didn’t you leave these ‘supplies’ at the door and leave. That’s what most people are doing, including me for my Dad. I wished my Dad happy birthday over the phone on Thursday.

“What you’ve done is irresponsible and breaks the regulations set out by the government. Essential supplies can be left on the doorstep, you don’t need to take chairs along and photograph yourself. You should just take the L on this one”, added Twitter user JC.

The MP’s sister, Rachel, could also face admonishment from police after she tweeted that she had visited her parents to deliver a “cake, a crumble and a lamb curry!”

Rachel Kinnock (@rnhk71) Thank you so very much for all the lovely messages to our dad, it means such a lot. We were able to safely deliver a cake, a crumble and a lamb curry! ⁦@SKinnock⁩ ⁦@HelleThorning_S⁩ pic.twitter.com/r65OgHa3Yg

It comes as a 13-year-old boy was arrested and his mother was “dealt with” as police forces across the country were given new powers to detain people failing to comply with coronavirus lockdown rules.

Ste Richardson, a senior section officer for West Yorkshire police, arrested the teenager under emergency legislation introduced on Thursday, which granted police powers to issue £60 on-the-spot fines or make arrests for breaches of the UK’s coronavirus rules.

The officer, who is based in Leeds, said on social media the boy had refused to give him any details and he had had “no choice” but to arrest him. It is unclear how the child had broken the lockdown rules.

In a now-deleted tweet, Richardson wrote: “Today I arrested a 13 year old male under the new coronavirus powers. The male refused to give me any details so I could take him home under the Act. He was arrested and taken to custody. His mother was dealt with for being a responsible person failing to comply.”

Ken Marsh, the head of the Metropolitan Police Federation, has previously said that the parents of older teenagers should be forced to pay fines if they were caught ignoring government guidance.

Elsewhere, a motorist was stopped by a motorway patrol on a 224-mile round trip to buy an item from eBay – with his wife in the boot, police said. The driver travelled from Coventry to collect the eBay purchase of windows in Salford, Greater Manchester, despite the public being warned only to make essential journeys due to the coronavirus pandemic.

After they picked up his purchase in Salford, the driver’s wife could not fit in the vehicle for the two-hour return journey south. She was travelling in the boot of the car when they were pulled over by a motorway patrol on the M6 in Cheshire, according to a tweet by the North West Motorway Police Twitter feed. Officers wrote out a traffic offence report for the driver.

On Friday, Derbyshire police were criticised after releasing drone footage of walkers at a beauty spot along with the warning that such exercise did not constitute “essential travel”. At the weekend the same force took the step of dying the normally clear waters of a picturesque quarry near Buxton black in an attempt to deter people from visiting.

Play Video 1:28 Police drone footage shames people using national park during UK lockdown – video

In North Yorkshire police have been carrying out spot checks near Harrogate and said checkpoints could appear anywhere, any time. Roadblocks were also set up in Plymouth, Devon, while in Cornwall 150 vehicles were checked in Penzance, Hayle and St Ives.

In Northern Ireland, police were preparing to target tourist sites and visitor locations, as they adopted new rules at 11pm on Saturday. Northern Ireland was the last part of the UK to develop regulations flowing from the new powers.

Officers across the UK have issued fines less than 24 hours after new laws were brought into force, the National Police Chiefs’ Council said. Those who ignore the tougher restrictions on movement could be hit with a £60 fine initially – reduced to £30 if paid within 14 days – and another for £120 for a second offence. Fines could reach £1,000-plus for repeat offenders.

Derbyshire police said they broke up a “massive party” on Saturday night involving 25 adults and children. The Derby West response section of the force tweeted: “Officers have just attended an address in absolute shock to find 25 adults and children having a massive party with speakers and karaoke. Everyone dispersed and hosts dealt with. It is clear people are still having complete disregard for the Government advice and rules.”

In Surrey, police broke up a house party in the Stanwell area, while in Cornwall walkers were criticised for ignoring lockdown advice and pouring into rural villages.

A spokesperson for Devon and Cornwall police said they were receiving regular reports from people concerned about others flouting the lockdown rules with about five calls an hour since 10am on Saturday.

Many forces have created hotlines to submit tip-offs about people allegedly flouting the social distancing rules, including gatherings of more than two people. West Midlands, Greater Manchester, and Avon and Somerset have also established online forums for those keen to report rule-breakers.