A BBC Radio 4 documentary, based on declassified tapes, has lifted the lid on the political manoeuvres of Richard Nixon, even before he was elected president.

In 1968 President Lyndon B Johnson thought Nixon was effectively sabotaging the Vietnam war peace talks.

Here he discusses with Senator Richard Russell how he believed Nixon's Chinese-American aide, Anna Chennault, was trying to persuade the US's South Vietnamese allies to pull out of the talks, promising Nixon would get them a better deal.

Listen to the whole programme on BBC Radio 4 at 20.00 GMT on Saturday or on the BBC iPlayer for seven days afterwards (UK users only).