RIVAL politicians have clashed in their first public debate in a Holyrood by-election campaign.

SNP, Labour, Conservative and Liberal Democrat candidates challenged each other on key issues in the Aberdeen Donside constituency. Central themes ranged from council tax policy to roads and attitudes to begging.

The seat was made vacant by the death of the SNP's Brian Adam.

In the debate, SNP candidate Mark McDonald, a regional North-east MSP, faced accusations that the Government hits Aberdeen with an unfair funding settlement, made worse by the council tax freeze.

Speaking on BBC Radio Scotland programme Brian Taylor's Big Debate, he said the Government was trying to improve taxation.

"When you have a situation where household bills are rising, where we know that people who are hit hardest by tax increases are those in the lowest income thresholds – pensioners, low-income families – we need to ensure they have a sense of security around their budget, particularly when the cost of things like energy is going up." Mr McDonald was joined by local government minister Derek Mackay to highlight efforts to "protect" people from a Westminster cut to council tax benefit.

Labour candidate Willie Young, an Aberdeen city councillor, said the funding settlement was being squeezed. "Aberdeen is getting ripped off," he told the audience. Mr Young also promoted a controversial policy to outlaw street begging.

"What we've found with the beggars in the city centre is that none are homeless," he said. "Some of them are begging for a living. It's atrocious."

He wants the Justice Secretary to allow the council to pass a by-law banning the practice, described by the SNP candidate as an attempt to criminalise people for being poor.

LibDem candidate Christine Jardine defended her party's actions at Westminster, including the "bedroom tax", and accused the SNP of acting in the interests of the Central Belt.

"They have a very Central Belt vision," she said. "The only thing they care about is trying to remain in power."

Conservative candidate Ross Thomson, also a city councillor, said he was committed to seeing through projects such as a third bridge over the River Don.

"I've delivered for the constituents I represent now, I will deliver for you in Holyrood - I'm making difference to quality of life."