Referring to reports last week of an imminent boardroom coup that failed to materialise, Mr Rowland said: 'They took me on. They started this nonsense. As the Mexican general said, 'As a friend I'm good, as an enemy I'm excellent'.'
He added: 'I shall pursue it hard and most forcefully. This has done me so much damage.'
Mr Rowland declared his intention to neutralise Mr Bock's option to buy most of his own remaining shares in 18 months' time - worth pounds 60m at current prices.
If the option were exercised Mr Rowland would use his wealth of nearly pounds 220m - now held in cash and Lonrho shares - to buy all or more of the stake back in the market, he said yesterday.
And he disclosed he had vetoed Mr Bock's choice of Eugene Anderson, former chairman of Ferranti, as chairman of Lonrho from next month at pounds 750,000 a year, and was backing instead the former diplomat Sir John Leahy, who is already on the board.
Mr Rowland, threatening legal action against Mr Cardew, said the PR man was paid by the company but was an adviser to Dieter Bock. He added: 'Bock was behind it.'
The Bock camp has long claimed that a gradual loss of support on the board, as older pro- Rowland directors retire, coupled with the exercise of the call option on the shares, will inevitably sideline Mr Rowland over time. But Mr Rowland has been infuriated by claims that he is a pounds 5.5m-a-year burden on the company.
Detailing his readiness to challenge any renewed move against him, Mr Rowland said Mr Bock had too much debt to keep the pounds 60m of shares if he exercised his option.
'He owes pounds 100m on his (existing) Lonrho shares. He owes against his other assets. He couldn't take up these shares.
'I have pounds 140m cash in the bank. I haven't got a single penny of debt to anybody,' he said. Mr Rowland said that with his Lonrho shares and pounds 8.5m a year in bank interest and dividends he would have almost pounds 220m. 'I have the means to take these people on. At my age, if not now, when?'
Widening the attack, Mr Rowland accused Mr Bock of not bringing 'a single penny's worth of business' to Lonrho's 680 companies since he had joined the trading conglomerate. It is understood that Mr Rowland has a substantial new African business deal of his own lined up.
Mr Bock was said to have been full of admiration for Mr Rowland's now much-criticised business dealings in Libya in the period just before he joined Lonrho.
And rejecting attacks on his expenses, claimed in the reports last week to have been a burden on the company, Mr Rowland said they had been audited by Peat Marwick and verified by the Inland Revenue every year for 20 years.
In the wake of claims about the high cost of his use of the company jet, he said Mr Bock and his wife Olga had just returned from a 14- day business trip in the Caribbean and Latin America.
Mr Rowland said his own wife Josie travelled on the company jet but it was always declared to the Inland Revenue at the equivalent first-class airline fair.
He threatened that last week's report in the Financial Times on the coup that never was could lead to legal action against Mr Cardew, whom he blames for the leaks.
Mr Cardew said: 'The whole statement that I had anything to do with it is nonsense from beginning to end.'
But Mr Rowland said: 'I believe I have the grounds. I am leaving it entirely to the solicitors and a top QC.' He said instead of his usual solicitors, Herbert Smith, he would use a litigation firm recommended by Mohamed Fayed, the Harrods boss with whom he made peace last year after a long feud.
Mr Rowland claimed Mr Cardew was paid pounds 150,000 a year by Lonrho, and that he should have immediately protested about the Financial Times report because he was responsible for the good image of the company, but did not.
He added: 'I have nothing against Dieter Bock. But whatever he does he has to consider very carefully that obviously I would be making counter-moves. One thing I am not without is some sort of courage to fight.'
Giving an insight into moves to find a new chairman, Mr Rowland said Mr Bock himself had suggested Sir John Leahy at one stage. This would make it hard for him to object now, he said.
Sir John had said on the first occasion that he would only take the job if both chief executives agreed. Mr Rowland's view was that Rene Leclezio should be allowed to finish his contract as chairman but this is now about to expire.
Mr Rowland said of Mr Anderson: 'Cardew produced him and introduced him to Bock. Bock introduced him to Paul Harper and Stephen Walls, two of the outside directors, and spoke to John Leahy on the telephone. Then I asked to meet him, to put my stamp of approval.'
The near-two-hour meeting started to go sour when Mr Anderson told him his salary would be pounds 750,000 a year, half paid outside the UK, and that he was expecting options on 10 million Lonrho shares at the current market price.
Mr Rowland said he inquired about Mr Anderson's experience of Africa, which he found limited. He then told Mr Anderson: 'I can't see you are the right bloke for us because 95 per cent of our interest is in Africa.' Morgan Grenfell, Lonrho's advisers, also criticised the proposal, Mr Rowland said, because there was no point in having an executive chairman and two chief executives.
Mr Rowland confirmed that David Owen had been considered for chairman a year ago but that 'Bock and Owen didn't get on.'
And he rejected press suggestions that he had been introduced to Nelson Mandela by Mr Bock - he said he had his own good contacts - or that it was Mr Bock who had initiated the flotation of the Ashanti Goldfields subsidiary. This had been mooted 18 months before Mr Bock joined, he said.
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