Speaking at Prime Minister's Question Time on Wednesday, Mr Blair said he did not want to "minimise" the tragedy but said it would be wrong to say Britons needed to fear for their safety when travelling by train.

He told the House collisions were down 12% in the last few years and the number of derailments had dropped by more than 20%.

Chia-Ching Wu (left) was studying for a Master's degree

His comments came on the day of the first of the funerals of the seven victims of the Potters Bar rail crash.

Chia-Hsin Lin, 30, was laid to rest at a private family ceremony on Wednesday.

Her parents were also presented with the Master's degree their daughter was studying for by the vice-chancellor of City University, London at the funeral in Watford.

Meanwhile, the fourth carriage - which had been wedged under the Hertfordshire station's canopy following the crash - was finally moved on Wednesday afternoon and was en route to Crewe for a detailed investigation.

Condolences

The faulty points which caused the crash are being taken to a laboratory in Buxton.

In his reply to a question by Liberal Democrat leader Charles Kennedy, Mr Blair offered his condolences publicly, to the families and friends of those involved in last Friday's rail crash which killed seven and injured more than 40.

He said: "The whole House will want to express its sympathy to the families of those that lost loved ones in the Potters Bar accident.

Safety within the railways is improving not declining

Prime Minister Tony Bair

"Our thoughts are with them particularly today since some of the first funerals of the victims are being held.

"Without minimising what took place at Potters Bar... I do feel it is important to stress, as people from within the industry have been stressing, that overall the railways and the issue of safety within the railways is improving, not declining."

Mr Blair had earlier given his backing to under-fire Transport Secretary Stephen Byers.

The prime minister said Mr Byers had got all of the big strategic decisions on the railways right and it was too early to speculate on the cause of the tragedy.