Liberal Democrat leader Jo Swinson has insisted she is not losing control of party candidates after a standard bearer stood down in a key marginal.
The comments came after Tim Walker said he would not contest Labour-held Canterbury because he did not want to split the Remain vote.
Ms Swinson insisted the Lib Dems would field another candidate in the Kent seat.
She said the party would also continue to stand against former Tory Cabinet minister David Gauke despite his outspoken criticism of Prime Minister Boris Johnson.
Asked if she was losing control of Lib Dem candidates, Ms Swinson told the PA news agency: “No. Clearly as Liberal Democrats we are committed to stopping Brexit.
“We have a healthy debate within the party and some candidates have made their own decisions.”
Ms Swinson was speaking as she visited a boxing gym in north London that trains youngsters in order to deter them from gang culture.
At the Total Boxer centre in Crouch End, Ms Swinson was shown punching moves by an instructor in a boxing ring.
For the boxing class, the Lib Dem leader sported a T-shirt with a spider on it and the words “Girly Swot”.
Ms Swinson told PA the spider was a tribute to Supreme Court judge Lady Hale who wore a spider broach when she delivered a judgment that proroguing Parliament in September had been unlawful.
Ms Swinson said she was “reclaiming” the phrase “girly swot”.
She said: “I was looking for a T-shirt for the ring and I thought it would do the job.”
Mr Johnson used the phrase to refer to ex-PM David Cameron.
Ms Swinson was at the gym to highlight a Lib Dem pledge to put £500 million a year into combating knife crime.
Mr Walker was due to contest Labour-held Canterbury but said he had asked his local party to withdraw his nomination papers as he wanted “no part” in allowing a Tory Brexiteer to win the seat.