Up to 50 peers are regularly "clocking in" to the House of Lords in order to claim a £300 daily attendance allowance, a former Conservative peer has claimed.

Lord Hanningfield – who served nine weeks of a nine-month sentence in 2011 for falsely claiming £28,000 in parliamentary expenses – suggested it was normal practice.

He made his comments after the Daily Mirror alleged that it had followed Hanningfield in July and found that on 11 of 19 days he spent less than 40 minutes in the Lords before returning to his home in Essex.

Hanningfield said the money went on "entertaining, meeting people, employing people", adding that he was a "full-time peer" who needed to be able to pay his electricity bill and buy food.

There is no suggestion that the former Conservative broke any rules but a Labour MP has called for parliamentary authorities to investigate the practice.

It will also inevitably lead to new calls for reform of the upper house and its allowance system.

While MPs are paid a salary, members of the House of Lords can claim a daily allowance of £300 if they attend a sitting.

Two peers have privately told the Guardian that it is well known among House of Lords staff that a small band of peers regularly appear at the House of Lords to register their appearance so they can claim the allowance.

One said: "You do see some peers come in and leave very quickly. They make sure that their appearance is registered in the chamber by a House of Lords staff member, who ticks them off a list. Or they can pass through the peers' entrance, where their presence is registered by another member of staff. Then they are entitled to their money.

"It is an abuse of expenses but it is not as widespread as Hanningfield suggests. Most of the people in the House of Lords have other forms of income and are mindful of abusing the system," the peer said.

Hanningfield's shortest attendance during the month was 21 minutes and the longest more than five hours, the Mirror said – with a total of £5,700 claimed in attendance allowance over the month and £471 in travel costs.

Confronted about the claims by the newspaper, Hanningfield said: "Lots of peers go in and check in for their expenses but they are using their expenses for a lot of things – entertaining, employing people."

"Clocking in and out of parliament is only part of being a peer."

"By the time I have people at home to help, time I have people in the House of Lords to help me, I spend something like £150 a day on expenses, so I don't really make any profit. I have to live, don't I?

I don't do anything else. How do you think I am going to eat, how am I going to pay my electricity bills?

"My income from the Lords will be about £30,000 a year, I pay about that in £18,000 in expense to other people, I'll end up with £12,000 a year."

He told the newspaper: "I can name 50 that do it. I see the same people go in and out as I do. I don't want to be persecuted."

The former leader of Essex county council, who was stripped of the Tory whip in 2010, said that in July he had been "trying to get myself back on track" after suffering a breakdown because of the expenses scandal. Since October, he said, he had "dramatically" upped his contributions in the Lords – speaking twice and attending committees.

The Mirror said that between April 2012 and July 2013 he claimed a total of £51,300 in attendance allowance despite making no speeches in the Lords chamber. "Being a lord is not just going in the House of Lords. It's the post you have. I have 15 letters a day, I have all sorts of things like that."

"I can do some of it at home, some of it at my office in the Lords. I admit I don't go much into the main chamber. If you look at my records since October it's changed dramatically because I've spoken twice.

"Let me explain again. I was trying to get myself organised after a nervous breakdown, a traumatic period."

The peer said that he had "made some mistakes" and paid back £70,000 in previous claims but continued to dispute his guilt and suggested he wished he had appealed against his conviction.

A guide for peers on claiming the £300 daily allowance says that it is available to those "who certify that they have carried out appropriate parliamentary work".

Another peer told the Guardian that many members of the upper house work very hard, but are not necessarily in the chamber if they are working on committees or campaigns in their offices.

"It is wrong to assume that if you are not in the main chamber or taking part in a vote that you are therefore claiming exes for nothing. Some of the most productive people in the House of Lords rarely go to the main chamber," the source said.

Any possible reform of the House of Lords's expenses system would have take into account the varied work of peers, the source added.

"It seems odd that we are paid for 'clocking in' but it is hard to see an alternative other than a basic rate of pay, which may work out as more expensive. And if you get rid of any expenses, the chamber would be stuffed full of the very rich, which is exactly what we have been trying to get away from," the peer added.

The Labour MP John Mann said: "There needs to be a full investigation into how he has been allowed to get away with it. We need to give the House of Lords a proper and transparent spring cleaning."