Peter Robinson's appeals for a shared future in Northern Ireland are aimed at wooing liberal Protestants rather than Catholics, a rival unionist has claimed.

In a string of high-profile gestures, the DUP leader has called for integrated education, recently attended a GAA match, and even expressed hopes of attracting the support of Catholic voters.

But former Ulster Unionist leader David Trimble said he believed the moves are actually aimed at securing the support of those unionists who have previously been deterred by the DUP's hardline past.

Lord Trimble also questioned whether Mr Robinson was bringing his party with him as he embarked on a more liberal agenda. "Is it for just window dressing?" Lord Trimble said. "Does it mean a significant shift in terms of the alignment of the party in the future?"

In an interview on the eamonnmallie.com website, Lord Trimble added: "I am doubtful as to whether the DUP can change its character to the extent that Robinson suggests. This is not something we can give a clear, hard and fast answer to."

He said the party had yet to shed sectarian baggage, adding: "I find it difficult to believe that party can be in a completely different place."

He said he believed the DUP leader's strategy was to woo liberal unionist voters, rather than the professed aim of reaching out to Catholic voters.

"What one has to do is to see how things develop," said Lord Trimble. "I would be looking, not so much at what one individual, all be it the leader, what he is saying - I'd be looking to see what other people are saying."

The Democratic Unionist MLA Jonathan Bell pointed to divisions in Lord Trimble's former party. Mr Bell said: "The DUP is absolutely committed to building a shared future in Northern Ireland, and unlike some others is united behind those efforts led by our party leader."

But Lord Trimble said Mr Robinson's calls failed to win the support of rank and file members at the DUP's last annual conference. "Putting it crudely - a journalist said to me with regard to one of the conference speeches in which Peter was saying these things that we're talking about - was that what they should have done was look at the audience - this was the bit that nobody clapped - nobody agreed," said the former Ulster Unionist leader.