New England captain Michael Vaughan moved quickly to dispel the notion on Wednesday that he would lack the authority and toughness required to lead the team successfully.

Vaughan, speaking at a news conference at Lord's on the eve of the second Test against South Africa, said: "I'm quite relaxed, but when I'm on the pitch I'm very focused.

"I'm pretty competitive and I expect players to play that way as well.

"There will be times when I have to have harsh words with the team, that's part of the job."

Vaughan took over as Test captain after Nasser Hussain quit at the end of the first test at Edgbaston.

Hussain said he felt stale after his four-year tenure but also suggested that his more authoritarian style of leadership might no longer be suitable after Vaughan adopted an easy-going style with the England one-day side.

"I'm a believer that the other 10 in the team also have to think. Whether it's the youngest guy or the oldest, I'll consider all their ideas," Vaughan added.

"I guess captaining over five days will be mentally tougher and more tiring but I think I am ready for the job."