What elections are there this year?
Seats on the Scottish Parliament and local councils, the Welsh assembly and most local authorities in England outside London are all up for grabs.
What's happening in Scotland?
This May sees the four-yearly elections for the Scottish Parliament, which runs the devolved Scottish government. Seats on all 32 unitary councils will be up for election as well.
What powers does the Scottish Parliament have?
It can pass laws on education, criminal justice, the NHS, business, agriculture, local government, social housing, transport and tourism and some other areas.
It also has the power to vary the basic rate of income tax, set by Westminster to cover the whole UK, by up to 3%.
Westminster retains control of areas like foreign policy, immigration, defence, social security, employment and national security.
Who controls the Scottish Parliament?
It is controlled by a Labour/Liberal Democrat coalition.
Labour has 50 seats, the Scottish National Party has 25, the Lib Dems and Conservatives both have 17, the Scottish Greens have seven, the Scottish Socialists have 4, Solidarity - the Socialist party set up by Tommy Sheridan - has two, the Scottish Senior Citizens Unity Party has one and there are five independents and one presiding officer.
There are also 32 local unitary authorities, which run local government services. From May 2007 they will be elected using the Single Transferable Vote.
How are MSPs elected?
MSPs are elected for four-year terms, by the "top up" system - a type of proportional representation.
There are 129 MSPs at Holyrood. 73 are constituency MSPs, 56 are regional "top-up" members.
Voters have two votes - one for a candidate in a constituency, and the second for a party - from this vote the "top-up" members are picked.
What is happening in Wales?
This May sees the four-yearly elections for the Welsh assembly. This runs the devolved government of Wales.
What powers does the Welsh Assembly have?
It can pass secondary legislation in some areas - meaning it can modify Acts of Parliament using Assembly Orders - but not make new Acts itself.
It can modify the details of Acts in areas including: agriculture, the environment, roads and transport, housing, social services, health, tourism and social services.
It does not have tax-raising powers but has some powers over government charges for services - like NHS prescriptions, charges for nursing homes and university tuition.
Isn't it getting more powers after the elections?
Yes. Under the Government of Wales Act 2006 - it will be able to make Assembly Measures - effectively passing laws, but only over those areas where it already has responsibility.
These will also be subject to a Westminster veto - the Houses of Commons and Lords will have to vote in favour of allowing the assembly to legislate in those areas.
The idea is to bypass the legislative "log jam" at Westminster, where laws prepared by the Welsh Assembly have to compete for time with bills prepared in Whitehall.
The Act also allows for the possibility of a referendum, to grant full law-making powers to the Welsh Assembly.
Who controls the Welsh Assembly?
Labour is the ruling party - although it was a minority government for much of the last term - and the First Minister is Rhodri Morgan.
There are 60 members of the Assembly (AMs), based in Cardiff, each elected for four years.
Labour has 29 seats, Plaid Cymru has 12, the Conservatives have 11, the Liberal Democrats have 6 seats and there are two independents, John Marek and Trish Law. The assembly is quite unusual as the executive (the government) and the parliamentary (legislative) branches are not legally separate - but integrated as a corporate body. The Government of Wales Act aims to change this.
How are AMs elected?
There are 40 AMs representing individual constituencies through the "first past the post" system, and five more regions elect another 20 from regional lists - a type of proportional representation.
Everyone has two votes - one to elect a constituency member and one vote to elect a regional member - the second vote is for a political party, not an individual.
Currently AMs delegate their executive powers to the First Minister, who is elected by the whole assembly. He gives responsibility for certain functions to the cabinet - made up of eight ministers.
What elections are there in England?
In England 32.8 million people will be able to vote - with seats being contested in 312 local authorities. In some councils one third of seats will be up for election, in others, the whole council will be elected. There are also mayoral elections in Bedford, Mansfield and Middlesbrough.
It is the biggest election in the local cycle in England, with about 10,500 council seats are up for grabs. This is because councils which are electing all their members have coincided with those electing one-third of councillors.
Elections are disproportionately in councils from the more rural and suburban areas of England - this year half of the seats are in just three of nine regions - eastern, south and south-west.
What powers do local councils have?
They vary between the different types of authorities. But powers can include setting council tax, as well as charges for things like parking tickets, overseeing street-cleaning, maintaining roads and parks, running libraries and schools, refuse collection, housing and social services, trading standards and environmental health - from fly tipping to noise pollution - and they grant planning permission for buildings.
When are the elections?
The elections will be held on Thursday 3 May 2007. Polls open at 7am and close at 10pm.
When will the results be known?
In England, 169 of the 312 councils where seats are being contested have decided to delay their counts until Friday - rather than starting straight after polls close and counting into the early hours.
This is largely because of new rules on postal votes which require election officers to double check at least 20% of signatures - but preferably 100% - accompanying ballot papers with those on the original applications for a postal vote.
It means a clear picture of the results will be unlikely to be available before Friday afternoon.
In Wales counts are expected to take place overnight. In Scotland the first results are expected at about 12.30am