Tottenham have been challenged to improve their offer to Emmanuel ­Adebayor as the Manchester City striker is stalling on signing a contract.

A £6million fee has been agreed between the clubs but Standard Sport understands that Adebayor’s advisors believe the 28-year-old deserves better terms than those offered.

It is thought Adebayor, who had a successful loan spell at White Hart Lane last season, has a four-year deal on the table, and discussions between the sides are ongoing. Adebayor has two years remaining on his £175,000-a-week deal at City, a basic salary that is far in excess of what Spurs’ highest earners collect.

Spurs hoped to bridge the gap by including a signing-on fee and clauses relating to bonuses and image rights but the player is still holding out for a more lucrative deal. Adebayor’s camp believe he would be about £1m worse off if he returns to north London.

The former Arsenal forward has offers from overseas, with clubs in Russia and Turkey thought to be interested in signing him, but at this stage, he would prefer to stay in England.

There is now a chance that Adebayor will run down his contract in Manchester before leaving the club for free but Spurs have not given up hope of reaching an agreement. City would prefer to sell Adebayor but if personal terms cannot be agreed, they might re-examine the option of another loan deal.

Last season, City contributed £105,000 to Adebayor’s wages every week. They would be loathe to do that again but if Adebayor cannot be reconciled with City manager Roberto Mancini, the champions might view this as the most pragmatic option.

New Spurs boss Andre Villas-Boas would like to bring in two forwards in this transfer window. Robert Lewandowski, of Borussia Dortmund, is thought to have been the first choice but he is currently deemed too costly.