NHS doctor
The NHS and immigration will be the two biggest issues at the 2015 General Election in Britain (Reuters)

There are two issues set to define the UK general election in 2015 in what will be a fierce and closely-contested political war.

On the one hand is immigration and on the other is the NHS.

The EU's cornerstone policy of free movement of labour has seen a large influx of European migrants to the UK in recent years, something that has concerned many voters and aided the rise of Nigel Farage's Eurosceptic party Ukip.

There is a perception that Britons are losing out on jobs to immigrants who are willing to work for less. And that public services, such as education, cannot cope with the increased demand.

Academic evidence shows that, on the whole, immigrants pay more in to the system than they take out.

Meanwhile the NHS, the sickly grandfather of public institutions and one voters are constantly worried about dying, is in crisis as a £30bn black hole in funding looms.

Many voters fear NHS privatisation, and the government is pushing through a number of controversial reforms, such as giving GPs the responsibility for managing their healthcare commissioning budgets.

And the two issues are connected: NHS staffing is propped up by immigration.

But which of the two is most important to you? Vote in our poll.