Media playback is unsupported on your device Media caption Nick Clegg: "Three-quarters of our manifesto is being delivered...more than the Conservatives"

Nick Clegg has said the Lib Dems are "punching above our weight" and delivering "real change" in government, as he seeks to rally Lib Dem activists.

At the party conference in Birmingham, Mr Clegg said Lib Dem ministers were "prepared to be awkward" and to "fight tooth and nail" for their beliefs.

And he said the party had brought "real change" to controversial NHS plans.

Activists are gathering after a tough year for the party amid anger over spending cuts and tuition fees.

Since entering into coalition with the Conservatives last year, there has been some unease within the wider party over the direction of government policies and the party suffered a drubbing in the English local elections in May.

In an opening address to party members on the first day of the conference, at Birmingham's International Convention Centre, the deputy prime minister addressed disputes within the party over coalition policies.

He said the party had "rows for a reason. To get NHS reform right, to keep fair taxes as our priority, to keep the government green".

'Real change'

But he said those seeking to drive a wedge between Liberal Democrats would not succeed as party members were "cut from the same cloth".

He told members that they had already made "real change" to the government's plans to restructure the NHS in England- which were put on pause after the Lib Dem spring conference voted to amend what they called a "damaging and unjustified" programme of change.

ANALYSIS Nick Clegg's challenge this week is to show that his party is making a difference in power, without evolving into an internal opposition. The Lib Dem leader will choose his battles carefully. He's happy to admit to differences with the Conservatives on Europe, the banks and human rights. But he believes key concerns over the NHS have been met and wants to avoid the conference being hijacked by demands for further concessions. There are some who want him to go further in standing up to the Tories, to reassert a stronger Liberal Democrat identity. But though he is happy to be transparent when there are differences, he also believes the public want the party to get on with the business of government. Read Carole's thoughts in full

And he said, pointing to a recent BBC Politics Show report suggesting 75% of Lib Dem pledges were being made into policy: "Not bad given we have just 8% of MPs in Westminster."

"Make no mistake - we are punching above our weight."

There was laughter in the hall as Mr Clegg joked about his coalition colleagues and the Daily Mail - which this week described Mr Clegg as "the most dangerous politician in Britain".

The Lib Dem leader has faced criticism from some that he has become too close to the Conservatives but he hinted at more disagreements between the two parties than has been publicised.

"We can't have all our fights in public. While times are hard, while people are struggling, the last thing people want to see is the nation's leaders squabbling and point scoring."

To applause from party members, he added: "That's why I can't tell you about every debate we have behind closed doors. But rest assured, we are fighting for Liberal values every day."

He said Lib Dem ministers were "prepared to be awkward" and the Conservatives had found out "on a daily basis" they were not there to make life easy.

'Political enemies'

The party suffered some of its heaviest criticism for supporting an increase in university tuition fees - having previously campaigned on a pledge to scrap them over six years.

But Mr Clegg said he was delivering manifesto promises on tax reform, the pupil premium and "building a new green economy".

He told activists the party "can be proud" of joining the coalition - despite describing the Conservatives as "our political enemies" - saying it would show voters that they could be "trusted to govern from the centre".

Thousands of party members have gathered in Birmingham after a difficult year for the Liberal Democrats, in which they suffered their worst English local elections for 30 years, losing nine councils and 747 councillors.

And they suffered a crushing defeat in the UK-wide referendum on changing the voting system - a long term goal of the party - in May.

Earlier activists failed in a bid to force a vote on controversial NHS changes. Although they voted in favour of allowing an emergency motion to be debated by 235 votes to 183, they failed to get the two thirds majority needed for it to be considered.

Party members have also voted in support of a motion calling on the government to scrap plans to cut the Employment and Support Allowance, the successor to incapacity benefit, after 12 months for many people. The vote will increase pressure on Lib Dem MPs and peers to seek to amend the legislation in Parliament.