Media playback is unsupported on your device Media caption Cameron and Clegg were asked if coalition "waters down" policies

David Cameron has said there will be no "let-up" in tough decisions on the economy and defended the coalition as "necessary" to solve the UK's problems.

Speaking on a visit to a factory in Essex ahead of Wednesday's Queen's Speech, the prime minister said many people were having "tough times".

He vowed to do more to help with living costs and help the UK "go for growth".

Deputy Nick Clegg said the economy could not be fixed "overnight" and the process could take many years.

The two were making a joint appearance ahead of the launch of the coalition's legislative programme for the next year and in the wake of poll losses for both the Conservatives and Lib Dems in last week's council elections.

These reverses have fuelled renewed tensions between the coalition partners, with Tory MPs demanding more purely Conservative policies.

The BBC's Norman Smith said the event was a show of unity and its setting - in a tractor factory in Essex - was designed to counter suggestions the government was out of touch and to provide a contrast with their 2010 "Rose Garden" press conference.

Mr Cameron said he realised families were finding it "difficult to make ends meet" and growth in the economy was much harder to come by than anticipated.

'Hard and difficult'

Despite this, he said there should be no "let-up" in the coalition's plans to cut spending, saying they were essential to stabilise the economy and deliver low interest rates.

"I am afraid we can't let up on the difficult decisions we have made to cut public spending and to get our deficit under control," he said. "I know it is hard and difficult but when you have a debt problem the one thing you must not do is to keep adding endlessly to that debt."

However, he promised to "redouble" the government's efforts to drive growth, through increased bank lending, support for new businesses and skills training.

SIGNIFICANT JOINT APPEARANCES November 2011: Launch of housing strategy

June 2011: NHS 'listening exercise'

March 2011: Q&A session

December 2010: End-of-year press conference

June 2010: Joint TV interview with Nick Robinson and BBC audience

May 2010: Rose Garden conference

As the UK confronted these serious challenges, it was vital that the Conservatives and Lib Dems continued to work together. Although the two parties did not agree on everything, he believed the coalition was "as important and necessary today as it was two years ago".

Mr Clegg said the economic recovery would be "painstaking" and the coalition should be "judged by its actions" over its five-year period.

"It is not something we are going to achieve overnight," he said. "Dealing with the deficit can sound a very, dry statistical exercise.

"I actually think we have a moral duty to the next generation to wipe the slate clean for them. We have set out a plan - it lasts about six or seven years - to wipe the slate clean to rid people of that deadweight of debt that has built up over time."

Lords debate

Both men denied the election of new French President Francois Hollande on a growth agenda signalled that voters were tiring of austerity measures such as spending cuts, tax rises and public sector pay freezes.

They also rejected the idea that the UK and other countries which prioritised measures to reduce debts were becoming isolated.

Their joint appearance was not, as billed, a renewal of their coalition vows. They largely do not need renewing.

Mr Cameron said it was a "myth" that Europe was divided into pro-growth and pro-austerity camps, pointing out that Mr Hollande was also calling for deficit reduction. Mr Clegg said the new French president agreed with the UK that recovery had to be built on "sustainable foundations".

Some Conservatives have been setting out an "alternative Queen's Speech" - calling for plans for reform of the House of Lords to be dropped in favour of more populist policies.

Both Mr Cameron and Mr Clegg said Lords reform was, by no means, their leading priority but Parliament should be allowed to debate the issue.

And Mr Clegg said he backed an elected Lords as "a smidgeon of democracy, I don't think, would go amiss because we have talking about it for 100 years".

'Radical measures'

All three of the main parties supported Lords reform in their 2010 manifestos. But Conservative MP David Ruffley warned his coalition partners against getting bogged down "in the minutiae" of the issue and urged them to focus on getting the economy back on its feet.

"We have to recognise that to get people into employment you have to start reducing the tax burden and if the Liberals don't want to join in that endeavour, then they might want to have an earlier meeting with the electorate at a general election," he told BBC Radio 4's World at One.

The BBC understands the commitment to hold the first elections to the Lords in 2015 will be included in the Queen's Speech but the changes will only go ahead on the basis Parliament can reach a consensus on the issue, which has proved impossible in the past.

Earlier, Labour leader Ed Miliband set out his party's alternative to the coalition during his own visit to Essex.

He said the government had run out of "excuses" for the "failure" of its economic policy.

The opposition has called for measures in the Queen's Speech to help families with the cost of fuel bills and train fares.

TUC general secretary Brendan Barber said: "The problem with the coalition's economic strategy is not just that it is unfair, but that it is not working.

"Rapid, deep spending cuts have helped send the economy back into recession."