Sirius Minerals, the company hit by planning problems in its controversial bid to set up a potash mine in Britain's North York Moors National Park, says it may replace its existing planning application with a new one.Sirius, which has warned of project delays to 2014 amid environmental concerns voiced by national park officials and locals, is considering withdrawing its planning application and making a new one on the same time-frame.It said a new application was likely to simplify planning documentation with no more delays and allow it to focus better on planners' concerns.Sirius also said a possible extension to the project boundary would require an identical planning application to North Yorkshire County Council.In the meantime Sirius said it was moving ahead with various planning work and studies and was holding regular meetings with the national park. Chief Executive Chris Fraser said: "The company is making good progress towards the approvals needed for the York Potash Project and the involvement of the county council is unlikely to impact our current time scales."PW