Mouldy baths to broken doors and cold showers – tenants’ complaints over the state of their properties are being laid bare in a spike of challenges against rental hikes.

Under a major shake-up brought by the Renters’ Rights Act in May, more people are disputing alleged above-market rent increases before a First Tier Tribunal, with many succeeding.

Of those, 36 per cent (45) saw the landlord succeed, with the rent determined matching their demand. However, in 41 per cent (52) the judge determined a partial rental increase below the landlord’s notice, and in 23 per cent (29) they said there should be no increase at all.

In one case, a tenant saw their rent decrease by £200 after challenging a £17-a-month rent increase.

Are you a landlord or tenant who has been through tribunal process? Email alexander.ross@independent.co.uk

The spike in cases is thought to have been driven by tenants no longer facing fears of eviction through section 21 as part of the Bill. Tenants launching a challenge also see the proposed hike delayed until a decision is made at tribunal, which can take several months.

Also, at the tribunal, the judge cannot set a rental price above what the tenant has asked for.

Reception to the reforms has been mixed, with organisations like London Renters Union pointing out cases where tenants have seen huge increases in rent despite challenging their landlord at a tribunal.

Meanwhile, landlord associations have complained of “potentially spurious claims” backed up by insufficient evidence.

Here we look at five cases of complaints over rental hikes:

In Leytonstone in London, a couple who were living in a three-bedroom terraced house for £550 a month faced a near-600 per cent increase to £3,000.

When they challenged the landlord, they said the rent should not be higher than £1,500. Photographs were shown of a dated kitchen and bathroom, and reports were shared of excess cold due to degraded double glazing, broken doors, worn carpets and mouse infestation.

The landlord said he had lacked money to improve the property and that a raise in rent would help fund the required work.

A rent of £2,000 a month was determined by the judge.

In the affluent village of Hoole in Chester, a couple challenged their landlords over raising the rent of their mid-terrace two-bedroom home from £1,200 to £1,310.

They said there had been no significant improvements to the property that justified the increase, and that they had faces issues of damp around windows, boiler problems, a faulty toilet and humidity.

The garden, they added, was in a neglected condition when they took on the tenancy, and they had improved it by investing considerable time restoring and maintaining it. The landlord responded by that their ask reflected the open market rental value of the property, which they said was in a good condition.

A judge determined the rent to be £1,285.

In Stockport, a couple complained over the proposed £25 increase in rent of their one-bedroom flat from £1,250 to £1,275.

They told a tribunal that the window blind were broken in every window in the property, while kitchen flooring was “battered” due to a defective washing machines. The shower goes cold every 30 seconds due to a new boiler being fitted.

Pictures were shared showing stained grouting and mould to the silicone sealant around the bath.

The tenants said: “Each year they have tried to up our rent more, even though we increased it to begin with, and have overpaid for two years, with things in the apartment breaking and not being fixed”

The judge said rent should not be increased on the evidence provided of the property’s current condition.

In Leeds, a man challenged his landlord over a second proposed 14 months, asking for £825 a month for the furnished flat in the city centre. The rent had been raised to £795 in August last year.

The tenant there had been several weeks over the past year when water use was impacted by maintenance issues and flooding incidents. He also said that the landlord had not made improvements to the property.

The judge went in favour of the tenant and determined the rent to be £795 a month.

In a modern residential housing complex on the bank of a canal in Salford in Manchester, one woman said a proposed rise in rent from £1229.73 to £1,268 a month would cause her financial hardship.

She said the third-floor flat lacked surrounding amenities of other housing developments with gyms, pools and cinemas. She said the features at the complex were standard, mislabelled as premium, and were not perks to justify a price increase.

An onsite pub that closed had not been replaced, she said.

The landlord said the complex provided a high specification of accommodation.

But the judge said market conditions meant rents in the area are below what the landlord suggests, determining monthly rent should be £1250.

The National Residential Landlords Association has raised concerns over evidence used in cases against landlords over property.

Chris Norris, chief policy officer at the National Residential, said: "It is entirely right that tenants should be able to challenge rents, if they feel that a landlord’s request is out of line with the market rate. However, it is disappointing that campaigners are actively trying to stall the system by flooding it with potentially spurious claims. It is essential that landlords and tenants have confidence in the service to work effectively.

“The most important thing for landlords to consider when reviewing rents is that they are able to support any uplifts with evidence, and should a challenge be brought against them it is imperative that they provide sufficient information about the specific property to support their proposal.”

Generation Rent, a group that provides a voice to private renters, said the Bill had taken away the risk faced by tenants on rents being increased further at a tribunal. It said the power imbalance between landlord and tenant had been addressed.

Dan Craw, deputy chief executive, said: “Homes are the foundations of our lives, which is why it is crucial that private renters can actually afford to keep a roof over our heads and live in homes that don't actively harm our health.

“The Renters' Rights Act has addressed the power imbalances between landlord and tenant, and it is encouraging that renters now feel able to challenge unaffordable rent increases without fear of being penalised for it. Under the old rules, a tenant who went to tribunal could end up paying more than their landlord had even asked for. That risk has gone, and these figures suggest tenants are using their new rights.”