The number of foreigners blocked at Irish air and sea ports is set to more than double this year when compared to 2013, according to new figures from the Department of Justice.

However, human rights campaign groups have voiced concern at the steady increase in “leave to land” refusals year on year, which have gone from 1,935 in 2013 to 3,450 in 2015.

Minister for Justice Frances Fitzgerald estimates more than 4,000 people will be denied entry to Ireland in 2016.

By the end of June, more than 2,000 refusals had already been issued.

“The overwhelming majority of persons who arrive at the frontiers of the State without permission to enter or reside here are refused leave to land,” Ms Fitzgerald said in response to a parliamentary question from Green Party TD Catherine Martin in July.

Passenger numbers and flights landing at Dublin Airport have increased significantly, said a Justice spokesman.

“These types of increases will generally lead to a proportionate increase in the numbers refused leave to land.”

Under long-standing international aviation rules, the airline that has brought a refused passenger is required to take that passenger back from where they have come.

Measures to deal with the enforcement of immigration control remain a key concern for the State and where it has been possible to increase the level of enforcement, this has been done,” he added.

Saying the figures illustrate a “very worrying trend”. the Migrant Rights Centre of Ireland’s director Edel McGinley said “there’s a lack of transparency and accountability” at ports, along with no means of complaining.

Net migration to Ireland will return in 2017, Ms McGinley added, and said: “We’re seen as a country that is accessible and that is open and welcoming towards immigrants and I think it’s very important that we remain that way.”

The Irish Refugee Council said last year 139 people from Afghanistan, 11 from Eritrea, 44 from Iran and 59 from Syria were among those refused leave to land.

“That means that Ireland refused leave to land to 253 people from refugee-generating countries last year,” said refugee council solicitor Stephen Collins.

Ireland could turn away 287 individuals with protection needs this year, he said.

Deportation orders

Meanwhile, the number of deportation orders served on individuals who are actually in the State, either as asylum seekers or for other reasons, has fallen significantly since 2013.

Then, 1,777 orders were signed. However, the figure for the first six months of 2016 is 468. A deportation order requires a person to leave.

It is only when they fail to do so that the State carries out the deportation.

However, figures from the Irish Naturalisation and Immigration Service show the number of these enforcements has already in the first six months of 2016 exceeded the annual totals for each previous year to 2013.

By the end of June, 286 deportations had been enforced in Ireland compared with 251 in all of 2015, 114 in 2014 and 209 in 2013.

The State has spent almost €4 million in the past three-and-a-half years on flights for deportees.

This includes €366,965 on charter flights and €3,558,221 on commercial flights.

Of the 3,790 individuals either deported or refused entry to Ireland in 2015, about 9.6 per cent came from Brazil, 9.2 per cent from Albania, 7.5 per cent from Nigeria, 7.4 per cent from South Africa and 6 per cent from Pakistan.

The immigration service classifies the origin of the remaining 60. 2 per cent as “others”.

Number refused leave to land

2016 (to June 30th): 2050

2015: 3,450

2014: 2,473

2013: 1,935

Number of deportation orders signed

2016: 468

2015: 765

2014: 733

2013: 1,777

Number of deportation orders enforced

2016: 286

2015: 251

2014: 114

2013: 209

Costs of deportation flights

2016: €883,290.39

2015: €962,529.64

2014: €852,847.05

2013: €1,226,519.51