Speaking at the UK launch of Edelman's 20th annual Trust Barometer, former MP for Hastings and Rye and BBC director general Tony Hall discussed the public's lack of trust and pessimism that has been fuelled by growing inequality, unethical business practices, dishonest politicians, and a fear of the pace of technological change.
The study, which polled 34,000 respondents in 28 markets, found only Russia ranked below the UK on trust.
Rudd, who resigned from cabinet and the Conservative party whip in September, described how branding someone a 'liar' in the House of Commons is unacceptable, but conceded that too many politicians today are too loose with the truth.
"Politicians are not holding themselves to agreed standard of truth, and low trust leads to contempt. I think it’s time for politicians to take responsibility for that and act," she said.
Rudd said politicans often "campaign in poetry, but govern in prose", and the Conservative majority offered the Government a chance to make a difference in the traditional Labour constituencies that had turned to the Tories.
She called for politicians to return to using facts, rather than emotion, in decision-making, and said it was vital to rebuild trust in politics.
"Most MPs I know are driven by change and purpose, but parties often act like bullies in the playground, as do the millions on social media," Rudd added.
Rudd said trust can only be won back with greater transparency and urged senior cabinet ministers to front up to media scrutiny.
"Where are they? The government are boycotting major news programs; trust wont be built by avoiding scrutiny," she added.
Hall, who will step down as director general in summer, said the need for quality news has never been clearer.
Although the BBC is still the UK's most trusted news source, he said the organisation had a responsibility to reverse the decline of local journalism - so politicians and institutions at every level are unable to avoid scrutiny.
"Local reporters have said the ability to hold local organisations to account is harder. It's no wonder people feel like their voices arent heard, and [the media] too London-centric."
"We also want to build up local radio stations. The future of the BBC is to be strong employer in UK communities - in the next 30 years only companies that are ethical will survive," he added.
Nearly a third of UK respondents feared they will be worse off in five years' time, three in five had lost faith in democracy, and more than half believed capitalism does more harm than good. The public blamed politicians for creating an environment of fear for their own political gain.