Tensions are mounting between the Hamas leadership based in Gaza and its exiled chief over the organisation's future strategy in the wake of the popular – and largely non-violent – Arab spring revolutions and the success of Islamist parties in elections.

Khaled Meshaal, the Islamist party's leader in Damascus, has indicated in recent weeks that Hamas is making a strategic turn away from armed struggle to popular non-violent resistance.

But Mahmoud Zahar, the most senior Hamas figure inside Gaza, told the Guardian: "There has been no change concerning our mode of thinking towards the conflict."

The rift, which has not been publicly acknowledged, follows Meshaal's endorsement of non-violent popular protest over armed resistance at a meeting six weeks ago with the Palestinian president Mahmoud Abbas, according to insiders. The pair discussed reconciliation between rival factions Fatah and Hamas before the next elections.

Last month the respected security and intelligence analysts Jane's reported that senior security sources within Hamas had told it "the group has accepted for the first time since its establishment in 1987 to move from armed to non-violent resistance".

However, in an interview in Gaza city, Zahar argued that "popular resistance" embraced military and civil resistance as long as both approaches were supported by a majority of the population.

Hamas, he said, "will not deny the right to resist by all means".

Gaza was no longer under occupation, he said, meaning that civil resistance was irrelevant there.

But the population still needed "to defend ourselves against aggression" from outside.

According to independent Gaza analyst Mkhaimar Abusada, there have been "major disagreements" between Zahar and Meshaal over Hamas's future direction and policies. He said: "Meshaal was crystal clear. He meant non-violent popular resistance and referred to the popular revolutions in Egypt and Tunisia. But Zahar is having a hard time swallowing that – especially at this critical time when people are talking about elections, and Hamas here does not want to be seen as giving up the armed struggle."

Meshaal, he said, believed that in the wake of the Arab spring, armed resistance was no longer appropriate or acceptable, and that Hamas needed to review its strategy to bring it into line with populist movements in the region.

Ghazi Hamad, Gaza's deputy foreign minister and a Hamas moderate, said: "We have to create a new strategy with our brothers in Egypt, Tunisia and Libya."

According to Gaza-based analyst Ibrahim Ibrach, Egypt's Muslim Brotherhood privately asked Hamas to "stop military activities and to work on politics. They want the situation to remain calm."

The "outside" leadership is thought to be more sensitive to regional change, whereas the "inside" leadership is focused on consolidating its domestic position. According to one Hamas insider, "Meshaal is trying to convince the leadership here that we have to open a new page, that isolation is a big burden."

Amid the Syrian uprising – in which Hamas has refused to back the regime, incurring the wrath of its sponsors there and in Tehran – the Damascus-based leadership is seeking a new base and may be inclined to curry favour with the politically-ascendent Islamist parties in the region.

"Meshaal is in a very delicate position," said Abusada. "Sooner or later he will have to leave Damascus." In contrast, "Hamas here in Gaza is on its own territory, the leadership is very determined and effective and feels secure."

Last month Ismail Haniyeh, Gaza's de facto prime minister, told a rally to mark Hamas's 24th anniversary: "Armed resistance is our strategic option and the only way to liberate our land, from the [Mediterranean] sea to the river [Jordan]."

Some observers believe Haniyeh is moving closer to Zahar's hardline position.

Since the war in Gaza ended three years ago Hamas has largely adhered to a ceasefire, and has attempted to stop other militant groups from firing rockets into Israel. However, it is thought to be rearming and training its forces in anticipation of a fresh assault by Israel on the territory.

According to Jane's, Hamas may for the time being "operate a twin-track policy of not completely renouncing violence, but also embracing non-violent resistance."