The Constitution is the social contract between government and the people and it determines how the country moves towards a better future, Finance Minister Pravin Gordhan said on Monday.

"Once our actions are seen to be incongruent with this important document of our democracy we must know that we have moved away from our duty to severe our people. We have broken that contract," he said in a recording of his address given at the memorial service of Umkhonto we Sizwe veteran, Shirish Nanabhai, provided by Netwerk24.

"This organisation the ANC (African National Congress) has been at the forefront of the struggle for most of the 20th century and it needs to rediscover and reclaim its original purpose."

This was unity, non-racialism, non-sexism and prosperity for all and not for a few, Gordhan said.

He said many of the country's state institutions were being tested. "They are also being influenced, or attempts are being made to influence them to do wrong and not serve democracy..."

Gordhan said those in leadership positions had a duty to leave these institutions stronger, better and morally more correct and more principled for the next generation.

Speaking about the Constitutional Court, following its Nkandla ruling, he said the judgment was a "testimony to the vibrancy and resilience of our democratic institution and all of us should be very proud of that".

Last week the Constitutional Court ruled that President Jacob Zuma failed to uphold the Constitution when he did not comply with Public Protector Thuli Madonsela's remedial action regarding payment for the upgrades to his Nkandla homestead.

It ruled that the National Assembly also failed to uphold the Constitution when it set aside Madonsela's report.

National Treasury has been ordered to determine the reasonable cost of the non-security features - namely the swimming pool, chicken run, cattle kraal, amphitheatre and visitors' centre.

Secondly, it had to determine how much of this amount Zuma should pay.

Gordhan said the struggle today was the fight against corruption, something struggle veterans such as Nanabhai would never stand for or defend.

He called on people to resist the capture of the country's hard won democracy. "Our children must inherit a well functioning state... which cares for our people."