Householders who fail to cut back high hedges could face charges of up to £200 a day, a Minister has said.
They may have to pay the money in addition to a maximum £1,000 fine for noncompliance with an order to trim the bushes.
Jim Fitzpatrick, a Minister at the Office of the Deputy Prime Minister, stressed that the powers, which come into force today, are only intended to be used as a last resort.
The legislation is designed to tackle the "misery" caused by high hedges and will give local authorities the power to act on them for the first time.
They will be able to step in to decide if the height of the hedge is unreasonable and if so what action needs to be taken.
Refusal to comply could result in fines of up to £1,000 being imposed at a magistrates' court.
Launching the new powers, Mr Fitzpatrick said: "If the court levies a fine of £1,000 and the individual does not comply with the order then the court can levy up to £200 a day, in addition to the £1,000."
On a bright sunny day in Kensington's Holland Park, the Minister removed his jacket and wielded a pair of shears next to a huge Leylandii - one of the types of hedge that has caused bitter rows between neighbours.
Mr Fitzpatrick said there were believed to be tens of thousands of such disputes across the UK which could drag on for "months, sometimes years", at times even descending into violence.
"Anecdotal evidence suggest that just putting this legislation in place has already led to a reduction in these disputes and common sense is prevailing.
"This legislation means that people whose lives have been made a misery will now be able to resolve these problems," the minister said.
The changes come as part of the Anti-Social Behaviour Act 2003 but are only now coming into force.
Officials say complaints will only be considered where the hedge under dispute is evergreen, over two metres high and "blocking out light, access, or reasonable enjoyment of the neighbours' property".
Campaigners have complained about charges of up to £ 550 that councils are expected to impose in order for people to make an official complaint about a hedge.
The Minister admitted such a fee would be "at the more expensive end" of the scale but would not say it was too much, adding that it was "down to councils" to decide.
The new process should mean complaints being resolved within 12 weeks of being referred to the council, the minister said.