By Chris Rogers BBC South West Political Editor

Every party is worried about the apathy factor

That is the comment you hear again and again as you talk to campaigning candidates in the South West.

There is a hard core of determined voters who will turn out come rain and shine, but they tend to be older, with a strong sense of a democratic duty.

They too are the ones who tend to take advantage of the rules expanding the option of postal voting.

A knife-edge battle is in prospect as Labour strive to keep control of the city they took in 2003, which they just retained by one seat last year.

The battle between Conservative and Liberal Democrat characterises so many of the district council elections Chris Rogers

In Labour's favour in Plymouth is the increasing evidence of the regeneration driving new life in the city.

The message from Labour leader Tudor Evans is clear. If you want to complain about Labour nationally, he says, write to your MP, don't kick your local councillor.

The Conservatives, of course, have had the sniff of electoral blood in their nostrils since their advance of 12 months ago.

Three gains would take them to the magic figure of 29, giving the Tories the one-seat majority instead of Labour.

Their difficulty is castigating an administration while viewing the evidence of success in a high-profile part of the city.

Delicious prospect

The Conservative group leader Vivien Pengelly turns the other side of the coin.

She points to the other end of Plymouth's shopping streets which struggle with the feel of the 1960s.

Standing in the Tories' way are the Liberal Democrats, never traditionally a force in Plymouth, but holders of two seats since group leader Karen Gillard defected from the Conservatives five years ago.

She has struggled with rifts and defections within the party, and has supported Labour's propositions in council.

Since last year's result she now contemplates a delicious prospect.

If Labour and the Tories come in neck and neck on 3 May, with a small coterie of Liberal Democrats it may well be Ms Gillard who will hold the balance of power.

Plymouth elects one third of its seats annually

In Torbay the fight for control is between Conservatives and Liberal Democrats.

With the Lib Dems holding more than twice as many seats as Conservatives, the answer should be simple.

But effective control is in the hands of the Conservatives because Torbay has the South West's only elected mayor.

He is a Conservative and the Liberal Democrats disagree with the whole concept of elected mayors.

Consequently they have refused to engage with the mayor's proposals, leaving him to work with the minority Conservatives.

Because of mayoral rules, however, the Tories only need to win two or three seats to constitute a third of the council, when they and the mayor can push through budget proposals.

It is the battle between Conservative and Liberal Democrat that characterises so many of the district council elections.

In rural areas Labour has been traditionally weak, while the other main strength is held by independent candidates.

In Torbay the fight for control is between the Tories and Lib Dems

In Kerrier and Caradon in Cornwall, and Mid Devon Council, independents have been the biggest group, leaving the council with no overall control.

Their performance is often unpredictable and the minor parties can also have unpredictable effects.

UKIP has 105 candidates, with the biggest concentrations in Kerrier (14) and Torbay (19).

Even the candidates admit a good result for them would be to win one seat on a council.

The Green Party has 14 candidates in Plymouth and 20 in North Devon. In previous elections, support has been encouraging, but not significant.

Make voting special

It does increase the choice available to the voters in certain councils, which we are told can only be a good thing. But it can only be a good thing if the voters turn out.

Every party is worried about the apathy factor and Plymouth Tories say they will do something about it.

If they win they plan to return Plymouth to elections for all the council every four years.

That, they hope, will make voting special again and make that trip to the polling station more worthwhile.