Intruders can come in many guises. Security systems may help protect you from burglars, but there is little you can do to stop your landlord entering your apartment uninvited if he has a mind to, particularly if there is no lease agreement.

While lease agreements generally state that the landlord must give reasonable notice before entering his property, whether it be for inspection, rent collection, or repairs, in reality tenants will rarely resort to legal action if the landlord or his representative decide to barge in unannounced.

Those with periodic tenancies have virtually no protection at all.

David Carroll returned home to his two-bedroom apartment off Pearse Street one evening to find his landlord watching TV in the sittingroom. The landlord had entered to conduct a spot check on the property and found that all was not to his liking.

"He demanded to know why we weren't cleaning the oven and said we were not taking care of the sofa that had been upholstered before we moved in three months previously. I can only guess that he had been upstairs wandering around the bedrooms. When I pointed out to him that he should have given us some notice, he told me if we didn't like it we could move out. The rent is relatively reasonable at £950 (€1,026) a month do we've decided to put up with his interference for now."

Cliona Murray and her flat-mate decided to move out of their three-bedroom flat over a pub on James Street after the letting agent called to inform her that the landlady was hiking the rent from £750 to £1,200 (€952 to €1,524).

The week before they were due to move out, she returned home to discover that all the internal doors were, swinging open.

"I twigged that the letting agent had been showing people around without notifying us," says Murray.

In a subsequent phone call to the managing director of the company, she said she believed there had been a break-in and intended to call the gardai. The managing director admitted he had shown people around the flat but said it was "spur of the moment".

However, the fact that the stair carpet had been hoovered and some fixtures and fittings cleaned indicated otherwise.

"He obviously knew he was going to bring someone in. I was fuming and told him I thought he was extremely unprofessional. The ridiculous thing is that if we had known he was going to show people around we would have tidied and cleaned up. The place was messy because we were in the process of moving.

"Out issue is not that he was showing people around, but that he didn't let us know first. He effectively broke into our apartment when the rent was paid and he had no right.

Jennifer Collins who lives in a two-bed apartment development off Dame Street was woken at 8.30 a.m. one morning by a knock on her bedroom door. She opened the door to find the caretaker standing in the inner hall of their apartment.

"He let himself in through the front door and said he had come to fix a radiator and a light. I asked him to come back in half an hour.

"When he returned he let himself in again while I was in the bathroom. I felt intimidated, not in the sense of !Oh my God, he's going to attack me' but more that I didn't know him and he could have been anybody. We have never been given the alarm code by the management agent."

According to Kieran Murphy of Threshold, few tenants will pursue errant landlords to the courts if there is a breach of privacy.

"That would be costly and many tenants are on short one or two-year leases. Most will want to maintain a reasonable relationship with the landlord and will grin and bear it or change the locks. You can change the locks provided you notify the landlord, but it is only of benefit if there is a lease agreement in place.

"In the case of those on a periodic tenancy, the landlord is likely to issue a retaliatory notice to quit."

Threshold does not have a breakdown of the number of male and female callers, but according to Murphy, female tenants can be particularly vulnerable if a male landlord or agent insists on letting themselves in.

The best initial course, says Murphy, is to try reasoning. "A large part of it can be ignorance of the legislation on the part of the landlord. They think it is their place, so they have a right to see what is happening there. If the tenant finds it helpful, they can mention their contact with us or we can write a letter on their behalf, but sometimes that only serves to escalate the situation."