Kirsty Williams said Lib Dems would support 'good value investment'
Welsh Liberal Democrat leader Kirsty Williams says the party may have to "look again" at a project due to create thousands of jobs in south Wales.
Lib Dem Treasury spokesman Vince Cable MP has proposed the £13bn St Athan defences training academy be scrapped.
The largest facility of its kind in the UK, St Athan would give specialist training to all the armed services.
Welsh Lib Dems initially said Dr Cable's idea was "not official Liberal Democrat policy".
The Ministry of Defence (MoD) announced two years ago that it was to train servicemen and women at the academy.
It has estimated the academy in the Vale of Glamorgan would create 2,500 jobs on site, with a further 750 to 1,500 additional jobs in the wider economy and up to 1,500 jobs in the construction phase.
Dr Cable included the defences training academy when he published an economic "recovery plan" containing proposals for cutting government spending.
He said the project was was too costly in the current economic climate.
In the hours after the publication, his Welsh colleagues put a statement on their party's website saying the examples given were "illustrative and represent only a first, rough attempt".
Labour and the Conservatives have criticised Dr Cable's proposal to axe the project.
Ms Williams, who is attending the party's UK conference in Bournemouth, said Dr Cable had been "right on the economy [and] right on the banking crisis".
She added: "But I am the leader of the Welsh party and it's my job to ensure that we get the best possible investment for Wales."
She said the Welsh party did know that Dr Cable and his department had been looking at St Athan when drawing up his recovery plan.
She added that she and Dr Cable had been having discussions on the past few days about "how to get the best value for the taxpayer".
She said: "We're going to have a look to see if it does represent really good value for money, and also to look at whether that project is really a realistic prospect."
Ms Williams said the UK government had already missed deadlines for the project.
She said: "Things should have been started by now - the government has failed to deliver for the people of the Vale of Glamorgan.
"What they said was going to happen is not reflected in the planning application.
"We need to look at what the reality is for St Athan and if it can secure good value investment for Wales, then we'll support it. It if doesn't, then we'll have to look again."